[#13468] Docs: upgrade MarkBind to v6

[Ayoub-glitsh]

Fixes #13468

Outline of Solution

• Upgraded markbind-cli used for developer documentation to v6.1.0.
• Verified that the documentation builds and serves correctly with the new MarkBind version.
• Confirmed that there are no custom Vue components or plugins in the documentation setup, so the Vue 2 → Vue 3 migration does not introduce breaking changes.
• Ran markbind build successfully; existing intra-link warnings are non-blocking and were already present.

[github-actions]

Hi @Ayoub-glitsh, thank you for your interest in contributing to TEAMMATES!
However, your PR does not appear to follow our contribution guidelines:

• Title must start with the issue number the PR is fixing in square brackets, e.g. [#<issue-number>]

Please address the above before we proceed to review your PR.

[Ayoub-glitsh]

Thanks for the clarification. I’ve updated the PR title to follow the contribution guidelines.

[samuelfangjw]

Please see the v5.5 changelogs as well, I believe there is a css file that needs to be updated.

[Ayoub-glitsh]

Thanks for the heads-up. I’ll review the v5.5 changelogs and check whether any CSS updates are required on our side.

[Ayoub-glitsh]

Thanks for the reminder! I confirmed we override docs/stylesheets/main.css. I’ve updated it to match the latest MarkBind template CSS (v5.5+/v6) and verified the docs still build successfully.

[samuelfangjw]

Thank you for your contribution!