Cleaning

[hikari-no-yume]

Hi.

First of all, thanks for making this plugin! We are using it in touchHLE and it has worked quite well for us.

Something that's caught me out occasionally is that the building is integrated, but not the cleaning. If I tell Android Studio to clean up the project, that isn't passed on to Cargo.

I'm not sure if this is good or bad… so I'm not sure if it should be changed. But maybe it'd be worth mentioning in the README.