Correct highlighted lines and wrap <comment>s in React fragment in …

…tutorial chapter 6 (#5058)

* Remove unnecessary highlight (line is generated by default)

* Keep React fragment as wrapping container

Avoid invalid JSX element array, similar to #5020

* Fix highlighting b/c that lines actually changed as well

* Add back highlight

Going to add this back for now since it's used in the example

Co-authored-by: Dominic Saadi <32992335+jtoar@users.noreply.github.com>

docs/docs/tutorial/chapter6/multiple-comments.md

@@ -67,11 +67,15 @@ export const Failure = ({ error }) => (
 )
 
 export const Success = ({ comments }) => {
+  return (
   // highlight-start
-  return comments.map((comment) => (
-    <Comment key={comment.id} comment={comment} />
-  ))
+    <>
+      {comments.map((comment) => (
+        <Comment key={comment.id} comment={comment} />
+      ))}
+    </>
   // highlight-end
+  )
 }
 ```