Add other C# folders

This adds all the folders *except* tutorials and LINQ. (Those will be in separate PRs)

Author: BillWagner

docs/csharp/how-to/index.md

@@ -15,8 +15,8 @@ There are several tips and tricks that are common C# developer practices:
 
 - [Initialize objects using an object initializer](../programming-guide/classes-and-structs/how-to-initialize-objects-by-using-an-object-initializer.md).
 - [Use operator overloading](../language-reference/operators/operator-overloading.md).
-- [Implement and call a custom extension method](../programming-guide/classes-and-structs/how-to-implement-and-call-a-custom-extension-method.md).
-- [Create a new method for an `enum` type using extension methods](../programming-guide/classes-and-structs/how-to-create-a-new-method-for-an-enumeration.md).
+- [Implement and call a custom extension member](../programming-guide/classes-and-structs/how-to-implement-and-call-a-custom-extension-method.md).
+- [Create a new method for an `enum` type using extension member](../programming-guide/classes-and-structs/how-to-create-a-new-method-for-an-enumeration.md).
 
 ### Class, record, and struct members
 

docs/csharp/methods.md

@@ -22,7 +22,7 @@ Methods are declared in a `class`, `record`, or `struct` by specifying:
 - The method name.
 - Any method parameters. Method parameters are enclosed in parentheses and are separated by commas. Empty parentheses indicate that the method requires no parameters.
 
-These parts together form the method signature.
+These parts together comprise the method signature.
 
 > [!IMPORTANT]
 > A return type of a method isn't part of the signature of the method for the purposes of method overloading. However, it's part of the signature of the method when determining the compatibility between a delegate and the method that it points to.
@@ -211,7 +211,7 @@ If a method takes an array as a parameter and modifies the value of individual e
 
 :::code language="csharp" source="snippets/methods/returnarray1.cs" id="snippet101":::
 
-## Extension methods
+## Extension members
 
 Ordinarily, there are two ways to add a method to an existing type:
 

docs/csharp/roslyn-sdk/get-started/syntax-transformation.md

@@ -57,7 +57,7 @@ Run the program again to see that you've built the tree for the code to add.
 
 ### Create a modified tree
 
-You've built a small syntax tree that contains one statement. The APIs to create new nodes are the right choice to create single statements or other small code blocks. However, to build larger blocks of code, you should use methods that replace nodes or insert nodes into an existing tree. Remember that syntax trees are immutable. The **Syntax API** doesn't provide any mechanism for modifying an existing syntax tree after construction. Instead, it provides methods that produce new trees based on changes to existing ones. `With*` methods are defined in concrete classes that derive from <xref:Microsoft.CodeAnalysis.SyntaxNode> or in extension methods declared in the <xref:Microsoft.CodeAnalysis.SyntaxNodeExtensions> class. These methods create a new node by applying changes to an existing node's child properties. Additionally, the <xref:Microsoft.CodeAnalysis.SyntaxNodeExtensions.ReplaceNode%2A> extension method can be used to replace a descendent node in a subtree. This method also updates the parent to point to the newly created child and repeats this process up the entire tree - a process known as _re-spinning_ the tree.
+You've built a small syntax tree that contains one statement. The APIs to create new nodes are the right choice to create single statements or other small code blocks. However, to build larger blocks of code, you should use methods that replace nodes or insert nodes into an existing tree. Remember that syntax trees are immutable. The **Syntax API** doesn't provide any mechanism for modifying an existing syntax tree after construction. Instead, it provides methods that produce new trees based on changes to existing ones. `With*` methods are defined in concrete classes that derive from <xref:Microsoft.CodeAnalysis.SyntaxNode> or in extension members declared in the <xref:Microsoft.CodeAnalysis.SyntaxNodeExtensions> class. These methods create a new node by applying changes to an existing node's child properties. Additionally, the <xref:Microsoft.CodeAnalysis.SyntaxNodeExtensions.ReplaceNode%2A> extension member can be used to replace a descendent node in a subtree. This method also updates the parent to point to the newly created child and repeats this process up the entire tree - a process known as _re-spinning_ the tree.
 
 The next step is to create a tree that represents an entire (small) program and then modify it. Add the following code to the beginning of the `Program` class:
 
@@ -78,7 +78,7 @@ Create a new <xref:Microsoft.CodeAnalysis.CSharp.Syntax.UsingDirectiveSyntax> no
 
 Run the program and look carefully at the output. The `newUsing` hasn't been placed in the root tree. The original tree hasn't been changed.
 
-Add the following code using the <xref:Microsoft.CodeAnalysis.SyntaxNodeExtensions.ReplaceNode%2A> extension method to create a new tree. The new tree is the result of replacing the existing import with the updated `newUsing` node. You assign this new tree to the existing `root` variable:
+Add the following code using the <xref:Microsoft.CodeAnalysis.SyntaxNodeExtensions.ReplaceNode%2A> extension member to create a new tree. The new tree is the result of replacing the existing import with the updated `newUsing` node. You assign this new tree to the existing `root` variable:
 
 [!code-csharp[create a new root tree](../../../../samples/snippets/csharp/roslyn-sdk/SyntaxTransformationQuickStart/ConstructionCS/Program.cs#TransformTree "Create the transformed root tree with the replaced namespace")]
 

docs/csharp/roslyn-sdk/tutorials/how-to-write-csharp-analyzer-code-fix.md

@@ -148,7 +148,7 @@ This cast always succeeds because your analyzer registered for changes to local
 
 Finally, you need to check that the variable could be `const`. That means making sure it is never assigned after it is initialized.
 
-You'll perform some semantic analysis using the <xref:Microsoft.CodeAnalysis.Diagnostics.SyntaxNodeAnalysisContext>. You use the `context` argument to determine whether the local variable declaration can be made `const`. A <xref:Microsoft.CodeAnalysis.SemanticModel?displayProperty=nameWithType> represents all of semantic information in a single source file. You can learn more in the article that covers [semantic models](../work-with-semantics.md). You'll use the <xref:Microsoft.CodeAnalysis.SemanticModel?displayProperty=nameWithType> to perform data flow analysis on the local declaration statement. Then, you use the results of this data flow analysis to ensure that the local variable isn't written with a new value anywhere else. Call the <xref:Microsoft.CodeAnalysis.ModelExtensions.GetDeclaredSymbol%2A> extension method to retrieve the <xref:Microsoft.CodeAnalysis.ILocalSymbol> for the variable and check that it isn't contained with the <xref:Microsoft.CodeAnalysis.DataFlowAnalysis.WrittenOutside%2A?displayProperty=nameWithType> collection of the data flow analysis. Add the following code to the end of the `AnalyzeNode` method:
+You'll perform some semantic analysis using the <xref:Microsoft.CodeAnalysis.Diagnostics.SyntaxNodeAnalysisContext>. You use the `context` argument to determine whether the local variable declaration can be made `const`. A <xref:Microsoft.CodeAnalysis.SemanticModel?displayProperty=nameWithType> represents all of semantic information in a single source file. You can learn more in the article that covers [semantic models](../work-with-semantics.md). You'll use the <xref:Microsoft.CodeAnalysis.SemanticModel?displayProperty=nameWithType> to perform data flow analysis on the local declaration statement. Then, you use the results of this data flow analysis to ensure that the local variable isn't written with a new value anywhere else. Call the <xref:Microsoft.CodeAnalysis.ModelExtensions.GetDeclaredSymbol%2A> extension member to retrieve the <xref:Microsoft.CodeAnalysis.ILocalSymbol> for the variable and check that it isn't contained with the <xref:Microsoft.CodeAnalysis.DataFlowAnalysis.WrittenOutside%2A?displayProperty=nameWithType> collection of the data flow analysis. Add the following code to the end of the `AnalyzeNode` method:
 
 ```csharp
 // Perform data flow analysis on the local declaration.

docs/csharp/roslyn-sdk/work-with-syntax.md

@@ -85,7 +85,7 @@ The statement node inside the block has a span indicated by the single vertical
 
 ## Kinds
 
-Each node, token, or trivia has a <xref:Microsoft.CodeAnalysis.SyntaxNode.RawKind?displayProperty=nameWithType> property, of type <xref:System.Int32?displayProperty=nameWithType>, that identifies the exact syntax element represented. This value can be cast to a language-specific enumeration. Each language, C# or Visual Basic, has a single `SyntaxKind` enumeration  (<xref:Microsoft.CodeAnalysis.CSharp.SyntaxKind?displayProperty=nameWithType> and <xref:Microsoft.CodeAnalysis.VisualBasic.SyntaxKind?displayProperty=nameWithType>, respectively) that lists all the possible nodes, tokens, and trivia elements in the grammar. This conversion can be done automatically by accessing the <xref:Microsoft.CodeAnalysis.CSharp.CSharpExtensions.Kind%2A?displayProperty=nameWithType> or <xref:Microsoft.CodeAnalysis.VisualBasic.VisualBasicExtensions.Kind%2A?displayProperty=nameWithType> extension methods.
+Each node, token, or trivia has a <xref:Microsoft.CodeAnalysis.SyntaxNode.RawKind?displayProperty=nameWithType> property, of type <xref:System.Int32?displayProperty=nameWithType>, that identifies the exact syntax element represented. This value can be cast to a language-specific enumeration. Each language, C# or Visual Basic, has a single `SyntaxKind` enumeration  (<xref:Microsoft.CodeAnalysis.CSharp.SyntaxKind?displayProperty=nameWithType> and <xref:Microsoft.CodeAnalysis.VisualBasic.SyntaxKind?displayProperty=nameWithType>, respectively) that lists all the possible nodes, tokens, and trivia elements in the grammar. This conversion can be done automatically by accessing the <xref:Microsoft.CodeAnalysis.CSharp.CSharpExtensions.Kind%2A?displayProperty=nameWithType> or <xref:Microsoft.CodeAnalysis.VisualBasic.VisualBasicExtensions.Kind%2A?displayProperty=nameWithType> extension members.
 
 The <xref:Microsoft.CodeAnalysis.SyntaxToken.RawKind> property allows for easy disambiguation of syntax node types that share the same node class. For tokens and trivia, this property is the only way to distinguish one type of element from another.