Review help links in onboarding

[TimoPtr]

Summary

This PR remove the last bits of TODO regarding the links. I've aligned them with iOS and a new PR is opened to update the doc for the new onboarding itself https://github.com/home-assistant/companion.home-assistant/pull/1264

Checklist

• [x] New or updated tests have been added to cover the changes following the testing guidelines.
• [x] The code follows the project's code style and best_practices.
• [x] The changes have been thoroughly tested, and edge cases have been considered.
• [x] Changes are backward compatible whenever feasible. Any breaking changes are documented in the changelog for users and/or in the code for developers depending on the relevance.

Any other notes

This can be merged directly in the base branch, or we wait and I'll merge it after the base branch is on main.