Add auth selection to the compare file command.

[emorris00]

Ability to select which account to compare file against, useful if there are production and sandbox instances.
Fixed some typos.
Fixed the eslint config?

I read that you aren't accepting external contributions after I finished doing this. So 🤷 close it if you want.

[lfpvillegas]

Hi @emorris00
Many thanks for your contribution. You are right, we are not accepting external contributions. Not because we don't want, but because of legal constraints.
Anyways, I'm not closing yet your review as we are going to do some internal inquiries.
Thanks.