📝 docs: update TODO.md wording with improvements phrasing

Changed the introductory text to use "suggestions for improvements"
instead of "planned improvements" to better reflect the advisory nature
of the document and avoid implying commitments to specific changes.

Author: w3bdesign

TODO.md

@@ -1,6 +1,6 @@
 # Next.js 15 Implementation TODO
 
-This document outlines the planned improvements for implementing Next.js 15 features in our project.
+This document outlines suggestions for improvements for implementing Next.js 15 features in our project.
 
 ## 1. Project Structure Reorganization