Update Release Notes/511.md

Co-authored-by: Ben Barham <[email protected]>

Author: DougGregor

Release Notes/511.md

@@ -25,7 +25,7 @@
   - Pull Request: https://github.com/apple/swift-syntax/pull/2359
 
 - `CodeBlockSyntax`
-  - Description: `CodeBlockSyntax` is now `SyntaxParseable`, so it can be used with string  interpolations.
+  - Description: `CodeBlockSyntax` is now `SyntaxParseable`, so it can be used with string interpolations.
   - Pull Request: https://github.com/apple/swift-syntax/pull/2361
 
 ## API Behavior Changes