Add Termux package

[zj-9]

This is a very helpful addon of fcitx5. Thank you for the great work!

BTW, there is already an fcitx5-hangul package for Termux. Maybe it'll help many other Chinese Termux users if an fcitx5-chinese-addons package is also added to the Termux repo.

Thanks!

[CoelacanthusHex]

This should be requested to Termux, not fcitx.

[wengxt]

we dont do any downstream packaging, nor have knowledge on how to do that.