feat: Run Jan server and UI on Android / Termux

[iAdanos]

Problem
Since Android app is not supported anymore, it would be great to make possible running Jan directly on Android / ARM Linux.

It can be possibly done by running Jan as server with Web UI in Termux / proot-distro under Termux.
Going that way, people would be able to use the same upstream app version and maintainers will not have a need to support a separate product.

Success Criteria

• There is a clear guide on how to run Jan server with UI (accessible from web browser) on Termux / Linux (e.g. Ubuntu aarch64).
• If required, a proper deb / binary package is provided with other Jan release artifacts

Additional context
A good example on what approach is proposed is code-server run instruction:

• https://coder.com/docs/code-server/latest/termux
• https://wiki.termux.com/index.php?title=Node.js
• https://medium.com/@olioxxayo/super-charge-your-coding-ability-with-termux-and-code-server-f6e84a4bd78a