Add command-line auto-completion support for sqlit CLI

[BishoyHanyRaafat]

It would be very helpful if the tab completion for the sqlit command-line interface for the popular shells
fish, bash, zsh etc..

[BishoyHanyRaafat]

might be helpful https://github.com/kislyuk/argcomplete

[BishoyHanyRaafat]

Let me know if you need my help in this one

[Maxteabag]

Seems a bit problematic that the user has to install and set up the auto completion themselves.

I don't think it's really worth it if they have to follow more instructional setup.