Add some basic zsh completions for asusctl

Added some very basic zsh completions for asusctl. On Arch (and I'm pretty sure Fedora as well, though I don't have a fedora system to test), zsh completions are kept under /usr/share/zsh/site-functions. I just added the completion script to the data directory and the relevant install and rm lines to the Makefile. I didn't bump the version of any of the crates as I haven't actually changed any of the rust code there, but let me know if I should still bump the version(s) anyways.