[DOCS] Removes low-level client docs and references (#6188) (#6198)

* [DOCS] Removes low-level client docs and references.

* [DOCS] Further adjustments.

* [DOCS] Adds note back without link.

Author: szabosteve

docs/client-concepts/connection-pooling/building-blocks/connection-pooling.asciidoc

@@ -29,9 +29,10 @@ this is https://blogs.msdn.microsoft.com/adarshk/2005/01/02/understanding-system
 
 So, what is a connection pool in NEST responsible for? It is responsible for managing the nodes in an Elasticsearch
 cluster to which a connection can be made and there is one instance of an `IConnectionPool` associated with an
-instance of `ConnectionSettings`. Since a <<lifetimes,single client and connection settings instance is recommended for the
-life of the application>>, the lifetime of a single connection pool instance will also be bound to the lifetime
-of the application.
+instance of `ConnectionSettings`. Since a single client and connection settings 
+instance is recommended for the life of the application, the lifetime of a 
+single connection pool instance will also be bound to the lifetime of the 
+application.
 
 There are five types of connection pool
 

docs/client-concepts/connection/configuration-options.asciidoc

@@ -15,10 +15,10 @@ please modify the original csharp file found at the link and submit the PR with
 [[configuration-options]]
 === Configuration options
 
-Connecting to Elasticsearch with <<elasticsearch-net-getting-started,Elasticsearch.Net>> and <<nest-getting-started,NEST>> is easy, but
+Connecting to Elasticsearch with <<nest-getting-started,NEST>> is easy, but
 it's entirely possible that you'd like to change the default connection behaviour. There are a number of configuration options available
-on `ConnectionConfiguration` for the low level client and `ConnectionSettings` for the high level client that can be used to control
-how the clients interact with Elasticsearch.
+on `ConnectionSettings` that can be used to control how the client interact with 
+Elasticsearch.
 
 ==== Options on ConnectionConfiguration
 

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

@@ -18,10 +18,6 @@ please modify the original csharp file found at the link and submit the PR with
 NEST is a high level Elasticsearch .NET client that still maps very closely to the original Elasticsearch API.
 All requests and responses are exposed through types, making it ideal for getting up and running quickly.
 
-Under the covers, NEST uses the <<elasticsearch-net,Elasticsearch.Net low level client>> to dispatch requests and
-responses, using and extending many of the types within Elasticsearch.Net. The low level client itself is still
-exposed on the high level client through the `.LowLevel` property.
-
 [float]
 === Connecting
 
@@ -45,8 +41,7 @@ var client = new ElasticClient(settings);
 ----
 
 In this example, a default index was also specified to use if no other index is supplied for the request or can be inferred for the
-POCO generic type parameter in the request. There are many other <<configuration-options,Configuration options>> on `ConnectionSettings`, which it inherits
-from `ConnectionConfiguration`, the type used to pass additional configuration options to the low level client in <<elasticsearch-net,Elasticsearch.Net>>.
+POCO generic type parameter in the request. There are many other <<configuration-options,Configuration options>> on `ConnectionSettings`.
 
 TIP: Specifying a default index is _optional_ but NEST may throw an exception if no index can be inferred for a given request. To understand more around how
 an index can be specified for a request, see <<index-name-inference,Index name inference>>.