Add reference to open-interpreter-termux in README

[MikeBirdTech]

Describe the changes you have made:

Added Android section to readme that links to https://github.com/Arrendy/open-interpreter-termux

Reference any relevant issues (e.g. "Fixes #000"):

Pre-Submission Checklist (optional but appreciated):

• I have included relevant documentation updates (stored in /docs)
• I have read docs/CONTRIBUTING.md
• I have read docs/ROADMAP.md

OS Tests (optional but appreciated):

• Tested on Windows
• Tested on MacOS
• Tested on Linux

[b9Joker108]

That is great, for the Termux implementation and its attendant documentation, to be expressly mentioned and pointed to, in the repository README.md, of the general over-arching ’code-interpreter’ (CI)project.

I have one additional request, please include explicit mention of the key-binding, to exit out of the CI interactive CLI environment, as I couldn't find that information in the repository information, nor in the project website, when I needed it.