Describe the feature you'd like
It would be really cool to have an autocomplete funtionality for byexample for bash (and possible other shells)

Describe alternatives you've considered (optional)
If installing the autocomplete is too complex, we could just print the necessary code (a shell script) for the autocomplete like pandoc does:

Generate a bash completion script.  To enable bash completion with pandoc, add this to your .bashrc:
           eval "$(pandoc --bash-completion)"

This is the place where the argparser is built: