Update README with security note on credentials

Added security note about managing credentials.

Author: rmodis1

README.md

@@ -47,6 +47,8 @@ python -c "import scripts.preflight_map_checks as pre; print(pre.__file__)"
 
 **Note:** The virtual environment must be activated whenever running scripts or the MCP server. You should see `(.venv)` in your terminal prompt.
 
+```
+
 ### 3. Configuration
 
 ⚠️ **Security Note:** Credentials are strictly managed via environment variables. Never commit `.env` files.