Handling of fish shell is different in urfave/cli; urfave/cli provides a generator for the shell script needed (probably because the fish completion syntax isn't flexible enough to let the application handle the completion at runtime? idk)
This means that the fish completion can become out of sync with the tea binary.
If we want to account for that, on each application run we need to
check if ~/.config/fish/conf.d/tea_completion.fish exists; if so
check if the tea version that wrote it is the currently running version
if not, rewrite the file.
Not sure this is worth the complexity & cost
It generates a completion that also suggests file names, which looks kinda messy: Didn't find a way around this, but there may be a way