Update index and add compatibility mode to connection section (#6003) (#6004)

* Update connection section of getting started

(cherry picked from commit 73b863f)

* Generate updated getting started doc

Co-authored-by: Steve Gordon <sgordon@hotmail.co.uk>

Author: github-actions[bot]

docs/client-concepts/high-level/getting-started.asciidoc

@@ -73,6 +73,17 @@ var settings = new ConnectionSettings(connectionPool)
 var client = new ElasticClient(settings);
 ----
 
+[float]
+==== Enabling the Compatibility Mode
+
+The Elasticsearch server version 8.0 is introducing a new compatibility mode that allows you a smoother upgrade 
+experience from 7 to 8. In a nutshell, you can use the latest 7.x Elasticsearch client with an 8.x Elasticsearch 
+server, giving more room to coordinate the upgrade of your codebase to the next major version.
+
+If you want to leverage this functionality, please make sure that you are using the latest 7.x client and set 
+the environment variable `ELASTIC_CLIENT_APIVERSIONING` to `true`. The client is handling the rest internally. 
+For every 8.0 and beyond client, you're all set! The compatibility mode is enabled by default.
+
 [float]
 === Using the Client in a Function-as-a-Service Environment
 

tests/Tests/ClientConcepts/HighLevel/GettingStarted.doc.cs

@@ -82,6 +82,19 @@ public void UsingConnectionPool()
 			var client = new ElasticClient(settings);
 		}
 
+		/**[float]
+		 * ==== Enabling the Compatibility Mode
+		 *
+		 * The Elasticsearch server version 8.0 is introducing a new compatibility mode that allows you a smoother upgrade 
+		 * experience from 7 to 8. In a nutshell, you can use the latest 7.x Elasticsearch client with an 8.x Elasticsearch 
+		 * server, giving more room to coordinate the upgrade of your codebase to the next major version.
+
+		 * If you want to leverage this functionality, please make sure that you are using the latest 7.x client and set 
+		 * the environment variable `ELASTIC_CLIENT_APIVERSIONING` to `true`. The client is handling the rest internally. 
+		 * For every 8.0 and beyond client, you're all set! The compatibility mode is enabled by default.
+		 * 
+		 */
+
 		/**[float]
 		 * === Using the Client in a Function-as-a-Service Environment
 		 *