docs: Spacing, capitalization, and punctuation
Description
When triaging issues, I thought #7636 (closed) probably needed some docs updates. I didn't think I'd seen any. Sure enough, !1731 (merged) came in while I was OOO.
This MR adds some light polish to the files changed in !1731 (merged).
Related issues and merge requests
- Related to feat(auth login): allow more non-interactive lo... (!1731 - merged) which didn't get a docs review while I was OOO
- Related to Lack of documentation on `glab auth login` (#7636 - closed)