Hide completion command in root.go

[peyton-alt]

Added lines in NewRootCmd hides function in entire and entire help.

entire completion works as expected, e.g:
entire completion zsh -> display shell code
source <(entire completion zsh) -> to activate
tabbing works to select entire commands

[Soph]

One more ask: Can you add a "--setup-shell" that can be added when you do enable via a none interactive command call? Default should be "false" and then when you add the flag it gets added 🤔

[gtrrz-victor]

Do we need "--setup-shell" flag ? brew install should take care of it: https://github.com/entirehq/homebrew-entire/blob/9bbbb5a6771eba89be71c8e9a86cee40fbf436f6/Formula/entire.rb#L17

[Soph]

@gtrrz-victor just making sure, since I just had issues understanding my own comment: I meant entire enable should get a --setup-shell command.

But ok, if we just do it on installation with homebrew and any other installation method we support, then yeah, we might not need it. Ok, let's ignore this. Can add it when we need it.