Add release notes

Author: j-f1

Release Notes/601.md

@@ -22,6 +22,10 @@
 - Added a new library `SwiftIfConfig`.
   - Description: This new library provides facilities for evaluating `#if` conditions and determining which regions of a syntax tree are active according to a given build configuration.
   - Pull Request: https://github.com/swiftlang/swift-syntax/pull/1816
+  
+- `SwiftBasicFormat` adds a method `indented(by:)` to all syntax node types.
+  - Description: This method indents a node’s contents using a provided piece of `Trivia`, optionally including the first line.
+  - Pull Request: https://github.com/swiftlang/swift-syntax/pull/2843
 
 ## API Behavior Changes
 
@@ -44,6 +48,10 @@
   - Description: `ClosureCaptureSyntax` now has an `initializer` property instead of `equal` and `expression`. Additionally, the `name` property is no longer optional.
   - Pull request: https://github.com/swiftlang/swift-syntax/pull/2763 
 
+- `Indenter` in `SwiftSyntaxBuilder` has been deprecated in favor of the new `indented(by:)` in `SwiftBasicFormat`.
+  - Description: Indenting is really more of a formatting operation than a syntax-building operation. Additionally, the `indented(by:)` method is more intuitive to use than a `SyntaxRewriter`. Aside from `BasicFormat`, there are no other public `SyntaxRewriter` classes in the package.
+  - Pull Request: https://github.com/swiftlang/swift-syntax/pull/2843
+
 ## API-Incompatible Changes
 
 - Moved `Radix` and `IntegerLiteralExprSyntax.radix` from `SwiftRefactor` to `SwiftSyntax`.