Add Janis as a Frontend Maintainer

Supporting Evidence listed in this issue: #14556 (closed)

Mentor Justification

It's hard to specify hard requirements for becoming a maintainer, which is why the documentation consists of flexible guidelines. Reviewers are encouraged to think of their eligibility for maintainership in the terms of "I could be ready at any time to be a maintainer as long as it is justified".

Please find @janis's ongoing work below with reference to his current reviews and how they compare to ongoing maintainer reviews and the MRs that are noteworthy.

• Janis FE Maintainership process - Historical MR... (#14556 - closed)

Before Merging (Mentor Tasks)

• Close any relevant trainee maintainer issues with a comment indicating that this merge request is being created, as (they are no longer required to become a maintainer).
• Mention the maintainers from the given specialty and ask them to provide feedback to the manager directly.
• Leave this merge request open for 1 week, to give the maintainers time to provide feedback.
• Ensure we have at least 2 approvals from existing maintainers.

Once This MR is Merged

1. Create an access request for maintainer access to gitlab-org/<project>.
2. Join the [at]frontend-maintainers slack group
3. Ask the maintainers in your group to invite you to any maintainer-specific meeting if one exists.
4. Let a maintainer add you to gitlab-org/maintainers/frontend
5. Announce it everywhere
6. Keep reviewing, start merging 🤘 😎 🤘