Broken relative links in non-main branch READMEs

[fed-franz]

When using (internal) relative links in README files in a non-main branch, the following occurs:

If reading the README from the file (i.e. when the path ends with .../README.md) the relative links work. For instance, if in repo/branch/dir1/dir2/README.md, the link [Parent](../README.md) correctly points to dir1/README.md.

However, if reading the README from the containing folder (i.e., when the path is .../folder), the relative links don't work. For instance, if in repo/branch/dir1/dir2/, the link [Parent](../README.md) points to repo/branch/README.md (as if it were an absolute link).

I tried to reproduce the bug with another repo but it seems to work fine there (despite the situation is the same, with nested folders and relative links, using the same browser and everything).

[github-actions[bot]]

Stale issue message

[paletteguy]

Would be nice to get it fixed.