Updates docs to try allow better customising and removes announcment banner.

[Real-MullaC]

Pull Request

Title

Updates docs to try allow better customising and removes announcment banner.

Type of Change

• [ ] New feature
• [ ] Bug fix
• [x] Documentation update
• [ ] Refactoring
• [ ] Hotfix
• [ ] Security patch
• [ ] UI/UX improvement

Description

Updates docs to try allow better customising and removes announcment banner. PR #2427 needs pushing before this PR.

Testing

I have tested this locally and banner is removed but custom css still is not.

Impact

Helps people customize the docs better.

Issue related to PR

[What issue/discussion is related to this PR (if any)]

• Resolves no issues

Additional Information

No

Checklist

• [x] My code adheres to the coding and style guidelines of the project.
• [x] I have performed a self-review of my own code.
• [x] I have commented my code, particularly in hard-to-understand areas.
• [x] I have made corresponding changes to the documentation.
• [x] My changes generate no errors/warnings/merge conflicts.