With Wikit no longer being actively maintained, it's documentation (in https://wmde.github.io/wikit) should be updated to notify any readers that Wikit is deprecated and that it has been superseded by Codex.

Acceptance Criteria

• The front page on https://wmde.github.io/wikit states the following: "Wikit has been deprecated and will no longer be maintained. For a similar design system and components library for Wikimedia projects, please see Codex"
• The message links to the codex documentation at https://doc.wikimedia.org/codex/latest/