Problem: I thought `--no-optional` would just ignore our top-level
optional dependencies, but it ends up ignoring deep optionl dependencies
like sodium-native. We really want these dependencies if we can build
them.
Solution: Remove the `--no-optional` suggestion and add a note about
what to do if Sharp doesn't install correctly, which is very likely
since Termux doesn't have libvips available.
Problem: The Termux install is new and exciting and there isn't any
documentation on how to experiment with it.
Solution: Add some documentation like we've done with systemd and
Docker so that we can collaborate and figure it out in the repo!
Christian Bundy