Add PHP open tag to examples (#1037)

* [Documentation] Add PHP open tag to examples

* Update docs/faq.txt

Co-authored-by: Andreas Braun <[email protected]>

Co-authored-by: Andreas Braun <[email protected]>

Author: OskarStark

source/reference/method/MongoDBCollection-find.txt

@@ -56,6 +56,8 @@ returned. It also limits the results to 5 documents.
 
 .. code-block:: php
 
+   <?php
+
    $collection = (new MongoDB\Client)->test->restaurants;
 
    $cursor = $collection->find(

source/reference/method/MongoDBCollection-findOne.txt

@@ -62,6 +62,8 @@ special BSON type, the query criteria for selecting a restaurant must use the
 
 .. code-block:: php
 
+   <?php
+
    $database = (new MongoDB\Client)->test;
 
    $zip = $database->zips->findOne(['_id' => '10036']);
@@ -80,6 +82,8 @@ returned.
 
 .. code-block:: php
 
+   <?php
+
    $collection = (new MongoDB\Client)->test->restaurants;
 
    $restaurant = $collection->findOne(

source/reference/method/MongoDBCollection-updateMany.txt

@@ -57,6 +57,8 @@ The following example updates all of the documents with the ``borough`` of
 
 .. code-block:: php
 
+   <?php
+
    $collection = (new MongoDB\Client)->test->restaurants;
 
    $updateResult = $collection->updateMany(

source/reference/method/MongoDBCollection-updateOne.txt

@@ -59,6 +59,8 @@ The following example updates one document with the ``restaurant_id`` of
 
 .. code-block:: php
 
+   <?php
+
    $collection = (new MongoDB\Client)->test->restaurants;
 
    $updateResult = $collection->updateOne(

source/tutorial/crud.txt

@@ -380,6 +380,8 @@ An equivalent filter could be constructed using the :query:`$regex` operator:
 
 .. code-block:: php
 
+   <?php
+
    [
        'city' => ['$regex' => '^garden', '$options' => 'i'],
        'state' => 'TX',