Wiki-only projects do not display URLs of an asciidoc link properly

What does this MR do and why?

Ensure that links in asciidoc wiki documents are correctly rewritten when displaying from the project main page.

Screenshots or screen recordings

before	after

How to set up and validate locally

• create a new project
• disable repository, and ensure wiki is enable (project settings)
• create a Home wiki page, in asciidoc format, with the content link:some/other/page[some page]
• go to the project's main page. You should see the home wiki page displayed.
• hover over the link and make sure the link points /-/wikis/some/other/page

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #254796 (closed)