fix: spelling and small doc updates

[ecroce]

Please verify the following:

• [ ] yarn test jest tests pass with new tests, if relevant
• [ ] yarn lint eslint checks pass with new code, if relevant
• [ ] yarn format:check prettier checks pass with new code, if relevant
• [ ] README.md (or relevant documentation) has been updated with your changes
• [ ] If this affects functionality there aren't tests for, I manually tested it, including by generating a new app locally if needed (see docs).

Describe your PR

Small typo fixes and a couple additions to existing pages that needed a little more info.