update documentation

Author: Mpdreamz

docs/client-concepts/high-level/serialization/modelling-documents-with-types.asciidoc

@@ -1,4 +1,4 @@
-:ref_current: https://www.elastic.co/guide/en/elasticsearch/reference/master
+:ref_current: https://www.elastic.co/guide/en/elasticsearch/reference/7.x
 
 :github: https://github.com/elastic/elasticsearch-net
 
@@ -7,7 +7,7 @@
 ////
 IMPORTANT NOTE
 ==============
-This file has been generated from https://github.com/elastic/elasticsearch-net/tree/master/src/Tests/Tests/ClientConcepts/HighLevel/Serialization/ModellingDocumentsWithTypes.doc.cs. 
+This file has been generated from https://github.com/elastic/elasticsearch-net/tree/7.x/src/Tests/Tests/ClientConcepts/HighLevel/Serialization/ModellingDocumentsWithTypes.doc.cs. 
 If you wish to submit a PR for any spelling mistakes, typos or grammatical errors for this file,
 please modify the original csharp file found at the link and submit the PR with that change. Thanks!
 ////