test guide "deploy_on_debian.md"

[MichaelKreil]

https://github.com/versatiles-org/versatiles-documentation/blob/main/guides/deploy_on_debian.md

[MichaelKreil]

While reviewing the documentation, several issues were found in this guide:

Fixed:

• Replaced hardcoded personal path WorkingDirectory=/home/abhi/Dev/echo-server with /home/versatiles/versatiles
• Added a > [!WARNING] admonition to flag that steps 5-7 are untested

Still needs testing/fixing:

• Test the full guide on a fresh Debian installation
• Verify the nginx configuration is correct and complete
• Verify the systemd service file works properly
• Ensure the WorkingDirectory and ExecStart paths are consistent with earlier steps
• Consider using tee or heredoc instead of nano for the nginx config