Restructure and modernize tour of C# (#18538)

* first draft finished.

* update and correct all snippets

* grammar check

* fix build errors and warnings.

* fix warnings.

* final proofread

* Apply suggestions from code review

Co-authored-by: Petr Kulikov <petr.kulikov@gmail.com>

* build error & incorect code fence.

* fix any redirections

* Apply suggestions from code review

Co-authored-by: Tom Dykstra <tdykstra@microsoft.com>
Co-authored-by: David Pine <david.pine@microsoft.com>

* respond to feedbck

And fix build warnings that crept in.

Co-authored-by: Petr Kulikov <petr.kulikov@gmail.com>
Co-authored-by: Tom Dykstra <tdykstra@microsoft.com>
Co-authored-by: David Pine <david.pine@microsoft.com>

Author: 4 people

.openpublishing.redirection.json

@@ -1764,14 +1764,46 @@
       "source_path": "docs/csharp/structs.md",
       "redirect_url": "/dotnet/csharp/language-reference/builtin-types/struct"
     },
+    {
+      "source_path": "docs/csharp/tour-of-csharp/arrays.md",
+      "redirect_url": "/dotnet/csharp/tour-of-csharp/features#arrays-collections-and-LINQ"
+    },
+    {
+      "source_path": "docs/csharp/tour-of-csharp/attributes.md",
+      "redirect_url": "/dotnet/csharp/tour-of-csharp/features#attributes"
+    },
+    {
+      "source_path": "docs/csharp/tour-of-csharp/delegates.md",
+      "redirect_url": "/dotnet/csharp/tour-of-csharp/features#delegates-and-lambda-expressions"
+    },
     {
       "source_path": "docs/csharp/tour-of-csharp/enums.md",
       "redirect_url": "/dotnet/csharp/language-reference/builtin-types/enum"
     },
+    {
+      "source_path": "docs/csharp/tour-of-csharp/expressions.md",
+      "redirect_url": "/dotnet/csharp/tour-of-csharp/program-building-blocks#expressions"
+    },
+    {
+      "source_path": "docs/csharp/tour-of-csharp/interfaces.md",
+      "redirect_url": "/dotnet/csharp/tour-of-csharp/types#interfaces"
+    },
+    {
+      "source_path": "docs/csharp/tour-of-csharp/program-structure.md",
+      "redirect_url": "/dotnet/csharp/tour-of-csharp/#program-structure"
+    },
+    {
+      "source_path": "docs/csharp/tour-of-csharp/statements.md",
+      "redirect_url": "/dotnet/csharp/tour-of-csharp/program-building-blocks#statements"
+    },
     {
       "source_path": "docs/csharp/tour-of-csharp/structs.md",
       "redirect_url": "/dotnet/csharp/language-reference/builtin-types/struct"
     },
+    {
+      "source_path": "docs/csharp/tour-of-csharp/types-and-variables.md",
+      "redirect_url": "/dotnet/csharp/tour-of-csharp/types"
+    },
     {
       "source_path": "docs/csharp/tuples.md",
       "redirect_url": "/dotnet/csharp/language-reference/builtin-types/value-tuples"

docs/csharp/methods.md

@@ -76,7 +76,7 @@ Types can override inherited members by using the `override` keyword and providi
 
 ## Passing parameters
 
-Types in C# are either *value types* or *reference types*. For a list of built-in value types, see [Types and variables](./tour-of-csharp/types-and-variables.md). By default, both value types and reference types are passed to a method by value.
+Types in C# are either *value types* or *reference types*. For a list of built-in value types, see [Types](./tour-of-csharp/types.md). By default, both value types and reference types are passed to a method by value.
 
 <a name="byval"></a>
 

docs/csharp/toc.yml

@@ -72,24 +72,12 @@
   items:
   - name: Introduction
     href: tour-of-csharp/index.md
-  - name: Program Structure
-    href: tour-of-csharp/program-structure.md
-  - name: Types and Variables
-    href: tour-of-csharp/types-and-variables.md
-  - name: Expressions
-    href: tour-of-csharp/expressions.md
-  - name: Statements
-    href: tour-of-csharp/statements.md
-  - name: Classes and objects
-    href: tour-of-csharp/classes-and-objects.md
-  - name: Arrays
-    href: tour-of-csharp/arrays.md
-  - name: Interfaces
-    href: tour-of-csharp/interfaces.md
-  - name: Delegates
-    href: tour-of-csharp/delegates.md
-  - name: Attributes
-    href: tour-of-csharp/attributes.md
+  - name: Types
+    href: tour-of-csharp/types.md
+  - name: Program building blocks
+    href: tour-of-csharp/program-building-blocks.md
+  - name: Major language areas
+    href: tour-of-csharp/features.md
 - name: What's new in C#
   items:
   - name: C# 8.0