docs(CODEOWNERS): add danmh to Figma maintainers

Justification

This feels weird, but it is the GitLab way so here goes... 😅

As part of the Trainee Design Maintainer for Figma process I have:

• Updated components to fix bugs the UI Kit. Reducing risk of inconsistency and improving designer efficiency.
  • Badge > 12px icon overrides maintain color in F... (#1280 - closed)
  • Badge > 12px and 16px icon Figma variants behav... (#1281 - closed)
  • fix(Toggle): Allows Figma component 'Label' tex... (#1246 - closed)
  • Split button bug fix (Figma)
• Reviewed updates to the UI kit against GitLab standards and wider industry practices. These reviews have opened dialog about the design system consumer experience, tested and identified regressions, found ways to simplify components, caught bugs before merge, collaborated on document within Figma, and contributed suggestions for improvements.
  • UI kit > Refactor banner (#1353 - closed)
  • Dropdown > Update styles (#1251 - closed)
• Contributed new features to the UI Kit using latest Figma features. Collaborating with maintainers and trainee maintainers on component vision and implementation details. Produced contribution guide to encourage wider contributions to the UI Kit. Spilt large migration effort into multiple smaller iterations to increase speed, improve the review experience, and reduce risk of introducing regressions. Contributed code updates to gitlab-ui to support refactor effort.
  • UI kit > Refactor badge (#1372 - closed)
  • fix(GlBadge): Update badge colours (gitlab-org/gitlab-ui!2944 - merged)
  • Migration video stream
• Testing of new maintainer techniques including the introduction of visual regression testing and using 'swap library' to test backwards compatibility.
• Collaborated on changes to the processes around Figma usage to make it easier to contribute, improve consistency, and increase maintainer efficiency.
  • docs(FigmaTemplate): Update Figma issue template (!2922 - merged)
  • docs(FigmaTemplate): add optional create versio... (!2972 - merged)
  • Draft: docs(UI Kit): Add deprecated components ... (!3066 - closed)

Opportunity areas

• I'd love the opportunity to pair with others to help bring their ideas and Figma components to the UI Kit. If you have ideas and would like someone to work with please reach out to me here or on Slack.

Additional resources

This MR follows on from work documented in Trainee Design Maintainer (design.gitlab.com, F... (gitlab-com/www-gitlab-com#13327 - closed) and an insatiable curiosity of design tools, and strategies and tactics while using them