Add TH links to TOC (dotnet#6508)

aspnetcore/toc.md

@@ -153,37 +153,44 @@
 ## [Route and app conventions](xref:mvc/razor-pages/razor-pages-conventions)
 ## [Razor SDK](xref:mvc/razor-pages/sdk)
 
-# [MVC](mvc/overview.md)
-## [Model binding](mvc/models/model-binding.md)
-### [Model validation](mvc/models/validation.md)
-## [Views](mvc/views/overview.md)
-### [Razor syntax](mvc/views/razor.md)
-### [View compilation](mvc/views/view-compilation.md)
-### [Layout](mvc/views/layout.md)
-### [Tag Helpers](mvc/views/tag-helpers/intro.md)
-#### [Create Tag Helpers](mvc/views/tag-helpers/authoring.md)
-#### [Use Tag Helpers in forms](mvc/views/working-with-forms.md)
-#### [Built-in Tag Helpers](mvc/views/tag-helpers/built-in/index.md)
-##### [Anchor Tag Helper](mvc/views/tag-helpers/built-in/anchor-tag-helper.md)
-##### [Cache Tag Helper](mvc/views/tag-helpers/built-in/cache-tag-helper.md)
-##### [Distributed Cache Tag Helper](mvc/views/tag-helpers/built-in/distributed-cache-tag-helper.md)
-##### [Environment Tag Helper](mvc/views/tag-helpers/built-in/environment-tag-helper.md)
-##### [Image Tag Helper](mvc/views/tag-helpers/built-in/image-tag-helper.md)
+# [MVC](xref:mvc/overview)
+## [Model binding](xref:mvc/models/model-binding)
+### [Model validation](xref:mvc/models/validation)
+## [Views](xref:mvc/views/overview)
+### [Razor syntax](xref:mvc/views/razor)
+### [View compilation](xref:mvc/views/view-compilation)
+### [Layout](xref:mvc/views/layout)
+### [Tag Helpers](xref:mvc/views/tag-helpers/intro)
+#### [Create Tag Helpers](xref:mvc/views/tag-helpers/authoring)
+#### [Use Tag Helpers in forms](xref:mvc/views/working-with-forms)
+#### [Built-in Tag Helpers](xref:mvc/views/tag-helpers/builtin-th/Index)
+##### [Anchor Tag Helper](xref:mvc/views/tag-helpers/builtin-th/anchor-tag-helper)
+##### [Cache Tag Helper](xref:mvc/views/tag-helpers/builtin-th/cache-tag-helper)
+##### [Distributed Cache Tag Helper](xref:mvc/views/tag-helpers/builtin-th/distributed-cache-tag-helper)
+##### [Environment Tag Helper](xref:mvc/views/tag-helpers/builtin-th/environment-tag-helper)
+##### [Form Tag Helper](mvc/views/working-with-forms.md#the-form-tag-helper)
+##### [Image Tag Helper](xref:mvc/views/tag-helpers/builtin-th/image-tag-helper)
+##### [Input Tag Helper](mvc/views/working-with-forms.md#the-input-tag-helper)
+##### [Label Tag Helper](mvc/views/working-with-forms.md#the-label-tag-helper)
 ##### [Partial Tag Helper](xref:mvc/views/tag-helpers/builtin-th/partial-tag-helper)
-### [Partial views](mvc/views/partial.md)
-### [Dependency injection into views](mvc/views/dependency-injection.md)
-### [View components](mvc/views/view-components.md)
-## [Controllers](mvc/controllers/actions.md)
-### [Route to controller actions](mvc/controllers/routing.md)
-### [File uploads](mvc/models/file-uploads.md)
-### [Dependency injection into controllers](mvc/controllers/dependency-injection.md)
-### [Test controllers](mvc/controllers/testing.md)
-## [Advanced](mvc/advanced/index.md)
-### [Work with the app model](mvc/controllers/application-model.md)
-### [Filters](mvc/controllers/filters.md)
-### [Areas](mvc/controllers/areas.md)
-### [Application parts](mvc/advanced/app-parts.md)
-### [Custom model binding](mvc/advanced/custom-model-binding.md)
+##### [Select Tag Helper](mvc/views/working-with-forms.md#the-select-tag-helper)
+##### [Textarea Tag Helper](mvc/views/working-with-forms.md#the-textarea-tag-helper)
+##### [Validation Message Tag Helper](mvc/views/working-with-forms.md#the-validation-message-tag-helper)
+##### [Validation Summary Tag Helper](mvc/views/working-with-forms.md#the-validation-summary-tag-helper)
+### [Partial views](xref:mvc/views/partial)
+### [Dependency injection into views](xref:mvc/views/dependency-injection)
+### [View components](xref:mvc/views/view-components)
+## [Controllers](xref:mvc/controllers/actions)
+### [Route to controller actions](xref:mvc/controllers/routing)
+### [File uploads](xref:mvc/models/file-uploads)
+### [Dependency injection into controllers](xref:mvc/controllers/dependency-injection)
+### [Test controllers](xref:mvc/controllers/testing)
+## [Advanced](xref:mvc/advanced/index)
+### [Work with the app model](xref:mvc/controllers/application-model)
+### [Filters](xref:mvc/controllers/filters)
+### [Areas](xref:mvc/controllers/areas)
+### [Application parts](xref:mvc/extensibility/app-parts)
+### [Custom model binding](xref:mvc/advanced/custom-model-binding)
 
 # [Web API](xref:web-api/index)
 ## [Controller action return types](xref:web-api/action-return-types)