feat(documentation): Adding model documentation (#4309)

modules/openapi-generator/src/main/resources/csharp-netcore/model_doc.mustache

@@ -1,6 +1,8 @@
 {{#models}}
 {{#model}}
 # {{{packageName}}}.{{modelPackage}}.{{{classname}}}
+{{#description}}{{description}}
+{{/description}}
 ## Properties
 
 Name | Type | Description | Notes

samples/client/petstore/csharp-netcore/OpenAPIClient/docs/ClassModel.md

@@ -1,4 +1,5 @@
 # Org.OpenAPITools.Model.ClassModel
+Model for testing model with \"_class\" property
 ## Properties
 
 Name | Type | Description | Notes

samples/client/petstore/csharp-netcore/OpenAPIClient/docs/File.md

@@ -1,4 +1,5 @@
 # Org.OpenAPITools.Model.File
+Must be named `File` for test.
 ## Properties
 
 Name | Type | Description | Notes

samples/client/petstore/csharp-netcore/OpenAPIClient/docs/Model200Response.md

@@ -1,4 +1,5 @@
 # Org.OpenAPITools.Model.Model200Response
+Model for testing model name starting with number
 ## Properties
 
 Name | Type | Description | Notes

samples/client/petstore/csharp-netcore/OpenAPIClient/docs/Name.md

@@ -1,4 +1,5 @@
 # Org.OpenAPITools.Model.Name
+Model for testing model name same as property name
 ## Properties
 
 Name | Type | Description | Notes

samples/client/petstore/csharp-netcore/OpenAPIClient/docs/Return.md

@@ -1,4 +1,5 @@
 # Org.OpenAPITools.Model.Return
+Model for testing reserved words
 ## Properties
 
 Name | Type | Description | Notes

samples/client/petstore/csharp-netcore/OpenAPIClientCore/docs/ClassModel.md

@@ -1,4 +1,5 @@
 # Org.OpenAPITools.Model.ClassModel
+Model for testing model with \"_class\" property
 ## Properties
 
 Name | Type | Description | Notes

samples/client/petstore/csharp-netcore/OpenAPIClientCore/docs/File.md

@@ -1,4 +1,5 @@
 # Org.OpenAPITools.Model.File
+Must be named `File` for test.
 ## Properties
 
 Name | Type | Description | Notes

samples/client/petstore/csharp-netcore/OpenAPIClientCore/docs/Model200Response.md

@@ -1,4 +1,5 @@
 # Org.OpenAPITools.Model.Model200Response
+Model for testing model name starting with number
 ## Properties
 
 Name | Type | Description | Notes

samples/client/petstore/csharp-netcore/OpenAPIClientCore/docs/Name.md

@@ -1,4 +1,5 @@
 # Org.OpenAPITools.Model.Name
+Model for testing model name same as property name
 ## Properties
 
 Name | Type | Description | Notes

samples/client/petstore/csharp-netcore/OpenAPIClientCore/docs/Return.md

@@ -1,4 +1,5 @@
 # Org.OpenAPITools.Model.Return
+Model for testing reserved words
 ## Properties
 
 Name | Type | Description | Notes