docs: emphasize NEW prompt creation in PR description

- Updated summary to highlight this creates a NEW prompt
- Added 'What's New' section explaining the gap being filled
- Clarified that before this PR there was no systematic codebase analysis
- Ensures PR description accurately reflects scope (creation not just enhancement)

Addresses user feedback about PR description focusing on enhancement
while skipping the fact that the prompt was also created.

Author: iaminawe

docs/PR_DESCRIPTION.md

@@ -1,8 +1,10 @@
-# PR: Add codebase context generation with evidence-based analysis
+# PR: Add codebase context generation prompt with evidence-based analysis
 
 ## Summary
 
-Creates a new `generate-codebase-context` prompt with comprehensive research-driven analysis capabilities. This prompt provides evidence-based codebase analysis with confidence assessment, supporting spec-driven feature development.
+**Creates a NEW `generate-codebase-context` prompt** with comprehensive research-driven analysis capabilities. This prompt provides evidence-based codebase analysis with confidence assessment, supporting spec-driven feature development.
+
+**What's New:** Before this PR, our workflow had no systematic codebase analysis step. This PR introduces a new prompt that fills that gap by analyzing codebases before feature development begins.
 
 ## What's New in This PR