docs: update the link int the FQA docs, the original link is 404 status now

[Hazel6869]

Please answer these questions before submitting a pull request, or your PR will get closed.

Why submit this pull request?

In the FQA docs, the original link is 404 status now

What changes will this PR take into?

Add new useful links

Please update this section with detailed description.

Related issues

fix/resolve #https://github.com/apache/apisix/issues/8077

Checklist:

• [x] Did you explain what problem does this PR solve? Or what new features have been added?
• [x] Have you added corresponding test cases?
• [x] Have you modified the corresponding document?
• [x] Is this PR backward compatible? If it is not backward compatible, please discuss on the mailing list first