Revise NEXT_RELEASE_NOTES.md for 2.58.0 release

Updated release notes for version 2.58.0 to reflect changes in the Performance panel and formatting corrections.

Author: crackedhandle

packages/devtools_app/release_notes/NEXT_RELEASE_NOTES.md

@@ -11,7 +11,7 @@ This is a draft for future release notes that are going to land on
 The 2.58.0 release of the Dart and Flutter DevTools
 includes the following changes among other general improvements.
 To learn more about DevTools, check out the
-[DevTools overview](/tools/devtools)
+[DevTools overview](/tools/devtools).
 
 ## General updates
 
@@ -23,7 +23,7 @@ TODO: Remove this section if there are not any updates.
 
 ## Performance updates
 
-- Show a message in the Performance panel when widget rebuild tracking is
+- Showed a message in the Performance panel when widget rebuild tracking was unavailable because the app was running in profile mode.
   unavailable because the app is running in profile mode. [#9755](https://github.com/flutter/devtools/pull/9755)
 
 ## CPU profiler updates