chore: switch to MIT license for wider adoption (v2.4.0)

- Changed from Sustainable Use License to MIT License
- Added attribution to Romuald Czlonkowski @ www.aiadvisors.pl/en
- Created ATTRIBUTION.md with easy attribution examples
- Updated package.json, README.md, and CLAUDE.md
- Added GitHub stars badge to encourage community support
- Bumped version to 2.4.0 to mark this significant change

This change allows:
✅ Unrestricted use in personal and commercial projects
✅ Easy integration into corporate environments
✅ Freedom to modify and distribute
✅ Hosting as a service without restrictions

The project remains focused on helping n8n builders work more efficiently.

🤖 Generated with Claude Code

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

ATTRIBUTION.md

@@ -0,0 +1,33 @@
+# Attribution
+
+## Using n8n-MCP in Your Project?
+
+While not legally required, we'd love it if you included attribution! Here are some easy ways:
+
+### In Your README
+```
+Built with [n8n-MCP](https://github.com/czlonkowski/n8n-mcp) by Romuald Czlonkowski @ [www.aiadvisors.pl/en](https://www.aiadvisors.pl/en)
+```
+
+### In Your Documentation
+```
+This project uses n8n-MCP (https://github.com/czlonkowski/n8n-mcp) 
+for n8n node documentation access.
+Created by Romuald Czlonkowski @ www.aiadvisors.pl/en
+```
+
+### In Code Comments
+```javascript
+// Powered by n8n-MCP - https://github.com/czlonkowski/n8n-mcp
+// Created by Romuald Czlonkowski @ www.aiadvisors.pl/en
+```
+
+## Why Attribution Matters
+
+Attribution helps:
+- Other developers discover this tool
+- Build a stronger n8n community
+- Me understand how the tool is being used
+- You get support and updates
+
+Thank you for using n8n-MCP! 🙏