fix: broken links in the README.md

Approver's checklist:

fix: #688

• The author has submitted the FSF Copyright Assignment and is listed in AUTHORS
• There is a test suite reasonably covering new functionality or modifications
• Function naming, parameters, return values, types, etc., are consistent with existing code
• This feature/change has adequate documentation added (if appropriate)
• No obvious mistakes / misspelling in the code

Thanks you for the changes!

This link is the only one that works for me (on Gitlab UI) prior to your changes. Can we just keep it as is?

Weird: the links work in the GitHub UI, just not in the Gitlab UI