Is your feature request related to a problem? Please describe.

(my opinion) Shell command completion provides a more interactive experience for finding the options you want to use, a bit more engaging and helpful than --help in certain cases. Lazygit does not provide it by default.

Describe the solution you'd like

Add a completion generator so that packagers can automatically add it or users can add it themselves when building from source

Describe alternatives you've considered

Creating a personal completion file or continue to reference --help

Additional context

Flaggy (the cli args parser dependency used for this project) has support for generating completions out of the box, but only on the latest version. We can upgrade our dependency to fix this. One breaking change they note is that is the way you specify flags with multiple values, which affects --use-config-file. Could just put it in release notes as a breaking change and seems ok to me.

An alternative is to switch to another package, but not sure if there's strong pull for that.