Debian Update to bookworm release & Nextcloud sync feature & Obisidan latest release

[drdada]

• Update Debian to Bookworm
• Nextcloud sync feature can now sync your MD files with your Nextcloud instance
  • Env-file contains the credentials for Nextcloud
  • Sync trigger have to be done manually (right click on the desktop)
• Dockerfile now download the latest release directly
• Update Readme regarding the clipboard menu