Backport #23152
`renderReadmeFile` needs `readmeTreelink` as parameter but gets
`treeLink`.
The values of them look like as following:
`treeLink`: `/{OwnerName}/{RepoName}/src/branch/{BranchName}`
`readmeTreelink`:
`/{OwnerName}/{RepoName}/src/branch/{BranchName}/{ReadmeFileName}`
`path.Dir` in
8540fc45b1/routers/web/repo/view.go (L316)
should convert `readmeTreelink` into
`/{OwnerName}/{RepoName}/src/branch/{BranchName}` instead of the current
`/{OwnerName}/{RepoName}/src/branch`.
Fixes#23151
Co-authored-by: yp05327 <576951401@qq.com>
Co-authored-by: Jason Song <i@wolfogre.com>
Co-authored-by: John Olheiser <john.olheiser@gmail.com>
Co-authored-by: silverwind <me@silverwind.io>
