I made a Android porting demo for Lilypond

[K.L.]

Hello guys.

It seems nobody has built lilypond for android yet. I made an experimental
demo myself.

Demo video: https://www.youtube.com/watch?v=ay13Dk6D60M
My blog: https://findlab.github.io/2020/10/23/lilypond-android/
Source: https://gitlab.com/k.l.lambda/lilypond

I know the official builder is GUB, but I'm not familiar with makefile. I
made a cmake building, and it seems not hard.

The prebuilt binary files of all dependency C modules with Android NDK may
be useful in future, if someone plans to make an official Android installer.

Also, by the way, I made a Lilypond nodejs C++ addon, so now nodejs
developers can access Lilypond in native API, avoiding disk I/O.

Hope this helps.