fixup! Allow @Metadata directives in doc comments

Author: franklinsch

Sources/docc/DocCDocumentation.docc/Reference Syntax/API Reference Syntax/Metadata.md

@@ -58,15 +58,15 @@ previous versions, @Redirected must be used as a top level directive.
 
 ### Usage in documentation comments
 
-You can specify `@Metadata` configuration in documentation comments for the following customizations:
-
-- ``Available``
-- ``CustomMetadata``
+You can specify `@Metadata` configuration in documentation comments to specify ``Available`` directives. Other metadata directives are 
+not supported in documentation comments.  
 
 > Note: Don't specify an `@Metadata` directive in both the symbol's documentation comment and its documentation extension file.
 If you have one in each, DocC will pick the one in the documentation extension and discard the one in the documentation
 comment.
 
+> Earlier versions: Before Swift-DocC 6.1, `@Metadata` was not supported in documentation comments.
+
 ## Topics
 
 ### Extending or Overriding Source Documentation