[DOCS] Restructures repo readme (#1339)

* [DOCS] REstructures repo readme.

* [DOCS] Makes a list of links under Usage.

(cherry picked from commit c817f68)

Author: szabosteve

README.md

@@ -10,13 +10,9 @@ This is the official PHP client for
 
 ## Contents
 
-- [Getting started](#getting-started-)
-- [Configuration](#configuration)
-  - [Use Elastic Cloud](#use-elastic-cloud)
+- [Installation](#installation)
+- [Connecting](#connecting)
 - [Usage](#usage)
-  - [Index a document](#index-a-document)
-  - [Search a document](#search-a-document)
-  - [Delete a document](#delete-a-document)
 - [Versioning](#versioning)
 - [Backward Incompatible Changes](#backward-incompatible-changes-boom)
 - [Mock the Elasticsearch client](#mock-the-elasticsearch-client)
@@ -26,165 +22,15 @@ This is the official PHP client for
 
 ***
 
-## Getting started 🐣
+## Installation
 
-Using this client assumes that you have an 
-[Elasticsearch](https://www.elastic.co/elasticsearch/) server installed and 
-running.
+Refer to the [Installation section](https://www.elastic.co/guide/en/elasticsearch/client/php-api/current/getting-started-php.html#_installation)
+of the getting started documentation.
 
-You can install the client in your PHP project using 
-[composer](https://getcomposer.org/):
+## Connecting
 
-```bash
-composer require elasticsearch/elasticsearch
-```
-
-After the installation you can connect to Elasticsearch using the 
-`ClientBuilder` class. For instance, if your Elasticsearch is running on 
-`localhost:9200` you can use the following code:
-
-```php
-
-use Elastic\Elasticsearch\ClientBuilder;
-
-$client = ClientBuilder::create()
-    ->setHosts(['localhost:9200'])
-    ->build();
-
-// Info API
-$response = $client->info();
-
-echo $response['version']['number']; // 8.0.0
-```
-
-The `$response` is an object of `Elastic\Elasticsearch\Response\Elasticsearch`
-class that implements `ElasticsearchInterface`, PSR-7 
-[ResponseInterface](https://www.php-fig.org/psr/psr-7/#33-psrhttpmessageresponseinterface)
-and [ArrayAccess](https://www.php.net/manual/en/class.arrayaccess.php).
-
-This means the `$response` is a [PSR-7](https://www.php-fig.org/psr/psr-7/)
-object:
-
-```php
-echo $response->getStatusCode(); // 200
-echo (string) $response->getBody(); // Response body in JSON
-```
-
-and also an "array", meaning you can access the response body as an
-associative array, as follows:
-
-
-```php
-echo $response['version']['number']; // 8.0.0
-
-var_dump($response->asArray());  // response body content as array
-```
-
-Moreover, you can access the response body as object, string or bool:
-
-```php
-echo $response->version->number; // 8.0.0
-
-var_dump($response->asObject()); // response body content as object
-var_dump($response->asString()); // response body as string (JSON)
-var_dump($response->asBool());   // true if HTTP response code between 200 and 300
-```
-
-## Configuration
-
-Elasticsearch 8.0 offers 
-[security by default](https://www.elastic.co/blog/introducing-simplified-elastic-stack-security),
-that means it uses [TLS](https://en.wikipedia.org/wiki/Transport_Layer_Security)
-for protect the communication between client and server.
-
-In order to configure `elasticsearch-php` for connecting to Elasticsearch 8.0 we
-need to have the certificate authority file (CA).
-
-You can install Elasticsearch in different ways, for instance using 
-[Docker](https://www.elastic.co/guide/en/elasticsearch/reference/current/docker.html)
-you need to execute the followind command:
-
-```bash
-docker pull docker.elastic.co/elasticsearch/elasticsearch:8.0.1
-```
-Once you have the docker image installed, you can execute Elasticsearch, for 
-instance using a single-node cluster configuration, as follows:
-
-```bash
-docker network create elastic
-docker run --name es01 --net elastic -p 9200:9200 -p 9300:9300 -it docker.elastic.co/elasticsearch/elasticsearch:8.0.1
-```
-
-This command creates an `elastic` Docker network and start Elasticsearch
-using the port `9200` (default).
-
-When you run the docker image a password is generated for the `elastic` user
-and it's printed to the terminal (you might need to scroll back a bit in the 
-terminal to view it). You have to copy it since we will need to connect to 
-Elasticsearch.
-
-Now that Elasticsearch is running we can get the `http_ca.crt` file certificate.
-We need to copy it from the docker instance, using the following command:
-
-```bash
-docker cp es01:/usr/share/elasticsearch/config/certs/http_ca.crt .
-```
-
-Once we have the `http_ca.crt` certificate and the `password`, copied during the
-start of Elasticsearch, we can use it to connect with `elasticsearch-php` as 
-follows:
-
-```php
-$client = ClientBuilder::create()
-    ->setHosts(['https://localhost:9200'])
-    ->setBasicAuthentication('elastic', 'password copied during Elasticsearch start')
-    ->setCABundle('path/to/http_ca.crt')
-    ->build();
-```
-
-For more information about the Docker configuration of Elasticsearch you can
-read the official documentation 
-[here](https://www.elastic.co/guide/en/elasticsearch/reference/current/docker.html).
-
-### Use Elastic Cloud
-
-You can use [Elastic Cloud](https://www.elastic.co/cloud/) as server with 
-`elasticsearch-php`. Elastic Cloud is the PaaS solution offered by 
-[Elastic](https://www.elastic.co).
-
-For connecting to Elastic Cloud you just need the `Cloud ID` and the `API key`.
-
-You can get the `Cloud ID` from the `My deployment` page of your dashboard (see 
-the red rectangle reported in the screenshot).
-
-![Cloud ID](docs/images/cloud_id.png)
-
-You can generate an `API key` in the `Management` page under the section 
-`Security`.
-
-![Security](docs/images/create_api_key.png)
-
-When you click on `Create API key` button you can choose a name and set the 
-other options (for example, restrict privileges, expire after time, and so on).
-
-![Choose an API name](docs/images/api_key_name.png)
-
-After this step you will get the `API key`in the API keys page. 
-
-![API key](docs/images/cloud_api_key.png)
-
-**IMPORTANT**: you need to copy and store the `API key`in a secure place, since 
-you will not be able to view it again in Elastic Cloud.
-
-Once you have collected the `Cloud ID` and the `API key`, you can use 
-`elasticsearch-php` to connect to your Elastic Cloud instance, as follows:
-
-```php
-$client = ClientBuilder::create()
-    ->setElasticCloudId('insert here the Cloud ID')
-    ->setApiKey('insert here the API key')
-    ->build();
-```
+Refer to the [Connecting section](https://www.elastic.co/guide/en/elasticsearch/client/php-api/current/getting-started-php.html#_connecting)
+of the getting started documentation.
 
 ## Usage
 
@@ -196,97 +42,13 @@ of Elasticsearch APIs.
 Here we reported the basic operation that you can perform with the client: 
 index, search and delete.
 
-### Index a document
-
-You can store (index) a JSON document in Elasticsearch using the following code:
-
-```php
-use Elastic\Elasticsearch\Exception\ClientResponseException;
-use Elastic\Elasticsearch\Exception\ServerResponseException;
-
-$params = [
-    'index' => 'my_index',
-    'body'  => [ 'testField' => 'abc']
-];
-
-try {
-  $response = $client->index($params);
-} catch (ClientResponseException $e) {
-  // manage the 4xx error
-} catch (ServerResponseException $e) {
-  // manage the 5xx error
-} catch (Exception $e) {
-  // eg. network error like NoNodeAvailableException
-}
-
-print_r($response->asArray());  // response body content as array
-```
-
-Elasticsearch stores the `{"testField":"abc"}` JSON document in the `my_index` 
-index. The `ID` of the document is created automatically by Elasticsearch and 
-stored in `$response['_id']` field value. If you want to specify an `ID` for the 
-document you need to store it in `$params['id']`.
-
-You can manage errors using `ClientResponseException` and 
-`ServerResponseException`. The PSR-7 response is available using 
-`$e->getResponse()` and the HTTP status code is available using `$e->getCode()`.
-
-### Search a document
-
-Elasticsearch provides many different way to search documents. The simplest 
-search that you can perform is a 
-[match query](https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-match-query.html),
-as follows:
-
-```php
-$params = [
-    'index' => 'my_index',
-    'body'  => [
-        'query' => [
-            'match' => [
-                'testField' => 'abc'
-            ]
-        ]
-    ]
-];
-$response = $client->search($params);
-
-printf("Total docs: %d\n", $response['hits']['total']['value']);
-printf("Max score : %.4f\n", $response['hits']['max_score']);
-printf("Took      : %d ms\n", $response['took']);
-
-print_r($response['hits']['hits']); // documents
-```
-
-Using Elasticsearch you can perform different query search, for more information 
-we suggest toread the official documention reported 
-[here](https://www.elastic.co/guide/en/elasticsearch/reference/current/search-your-data.html).
-
-### Delete a document
-
-You can delete a document specifing the `index` name and the `ID` of the 
-document, as follows:
-
-```php
-use Elastic\Elasticsearch\Exception\ClientResponseException;
-
-try {
-    $response = $client->delete([
-        'index' => 'my_index',
-        'id' => 'my_id'
-    ]);
-} catch (ClientResponseException $e) {
-    if ($e->getCode() === 404) {
-        // the document does not exist
-    }
-}
-if ($response['acknowledge'] === 1) {
-    // the document has been delete
-}
-```
-
-For more information about the Elasticsearch REST API you can read the official 
-documentation [here](https://www.elastic.co/guide/en/elasticsearch/reference/current/rest-apis.html).
+* [Creating an index](https://www.elastic.co/guide/en/elasticsearch/client/php-api/current/getting-started-php.html#_creating_an_index)
+* [Indexing a document](https://www.elastic.co/guide/en/elasticsearch/client/php-api/current/getting-started-php.html#_indexing_documents)
+* [Getting documents](https://www.elastic.co/guide/en/elasticsearch/client/php-api/current/getting-started-php.html#_getting_documents)
+* [Searching documents](https://www.elastic.co/guide/en/elasticsearch/client/php-api/current/getting-started-php.html#_searching_documents)
+* [Updating documents](https://www.elastic.co/guide/en/elasticsearch/client/php-api/current/getting-started-php.html#_updating_documents)
+* [Deleting documents](https://www.elastic.co/guide/en/elasticsearch/client/php-api/current/getting-started-php.html#_deleting_documents)
+* [Deleting an index](https://www.elastic.co/guide/en/elasticsearch/client/php-api/current/getting-started-php.html#_deleting_an_index)
 
 ### Versioning
 

docs/getting-started.asciidoc

@@ -8,7 +8,6 @@ operations with it.
 [discrete]
 === Requirements
 
-* TO DO
 * http://getcomposer.org[composer]
 
 If you don't have composer you can install it by running the following commands: