Write better documentation

[1player]

The README was written when host-spawn was only a proof-of-concept, to demonstrate the issues in flatpak-spawn --host were relatively easy to fix. Now that it's starting to be used as a replacement of flatpak-spawn itself, it's better to rewrite the docs to explain how it works and how to set it up.

[pioupia]

Can you briefly explain how to set it up please?

[1player]

@pioupia please use this discussion for usage questions: #23

But in simple terms, my suggested setup, provided you are using it with distrobox or toolbox, is to put the binary in /usr/local/bin inside the container and that's all that's needed. Calling host-spawn from within the container should open a shell on the host, and running host-spawn <command> will run the command on the host.