chore: fix Creative Intelligence Suite link in README

Fixed broken link to CIS documentation that was pointing to uppercase
README.md. Now correctly points to lowercase readme.md file.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

README.md

@@ -124,7 +124,7 @@ Each agent brings deep expertise and can be customized to match your team's styl
 - **Creative Intelligence Suite (CIS)** - Innovation & problem-solving
   - Brainstorming, design thinking, storytelling
   - 5 creative facilitation workflows
-  - [→ Creative Workflows](./src/modules/cis/README.md)
+  - [→ Creative Workflows](./src/modules/cis/readme.md)
 
 ### Key Features