move android docs to its own docs file

docs/meshchat_on_android_with_termux.md

@@ -0,0 +1,31 @@
+# MeshChat on Android
+
+It's possible to run on Android from source, using [Termux](https://termux.dev/).
+
+You will need to install a few extra dependencies and make a change to `requirements.txt`.
+
+```
+pkg upgrade
+pkg install git
+pkg install nodejs-lts
+pkg install python-pip
+pkg install rust
+pkg install binutils
+pkg install build-essential
+```
+
+You should now be able to follow the [how to use it](../README.md#how-to-use-it) instructions above.
+
+Before running `pip install -r requirements.txt`, you will need to comment out the `cx_freeze` dependency. It failed to build on my Android tablet, and is not actually required for running from source.
+
+```
+nano requirements.txt
+```
+
+Ensure the `cx_freeze` line is updated to `#cx_freeze`
+
+> Note: Building wheel for cryptography may take a while on Android.
+
+Once MeshChat is running via Termux, open your favourite Android web browser, and navigate to http://localhost:8000
+
+> Note: The default `AutoInterface` may not work on your Android device. You will need to configure another interface such as `TCPClientInterface`.