#34945: add a div id to the readme section in the project overview

What does this MR do?

• Add a id='readme' to the readme div in the project overview
• Change the behavior of the readme button in the project overview, adding a same-page navigation link

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
  • Has been reviewed by Backend
  • Has been reviewed by Database
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together

What are the relevant issue numbers?

Closes #34945 (closed)