Add basic installation info to README

Author: spawnia

README.md

@@ -1,3 +1,18 @@
 # Laravel GraphQL Playground
 
-Easily integrate GraphQL Playground into your Laravel project
+Easily integrate [GraphQL Playground](https://github.com/prismagraphql/graphql-playground) into your Laravel projects
+
+    composer require mll-lab/laravel-graphql-playground
+
+If you are using Laravel < 5.4, add the service provider to your `config/app.php`
+
+````php
+'providers' => [
+    // Other providers...
+    MLL\\GraphQLPlayground\\GraphQLPlaygroundServiceProvider::class,
+]
+````
+
+You may publish the configuration and/or the views:
+
+    php artisan vendor:publish