fix: rename application from Keep to Mento in UI and docs

- Update sidebar.tsx to display "Mento" instead of "Keep"
- Update README.md title from "Keep Notes" to "Mento"
- Update DOCKER_DEPLOYMENT.md references to "Mento"
- Update deploy.sh script comments to use "Mento"
- Add DOCKER-SETUP.md with Docker configuration guide

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

keep-notes/DOCKER_DEPLOYMENT.md

@@ -1,6 +1,6 @@
 # 🐳 Docker Deployment Guide for Proxmox
 
-Complete guide to deploy Keep Notes on Proxmox using Docker Compose.
+Complete guide to deploy Mento on Proxmox using Docker Compose.
 
 ## 📋 Prerequisites
 
@@ -375,7 +375,7 @@ usermod -aG docker ubuntu
 # Add: features: nesting=1,keyctl=1
 ```
 
-Then deploy Keep Notes as described above.
+Then deploy Mento as described above.
 
 ## 📚 Additional Resources