Index pages edit button gives the wrong link

Because some pages are dynamically moved by pulp-docs, the edit-button gives the wrong URL.

E.g:

```
# page
https://pulpproject.org/pulp_python/#summary

# wrong edit-btn url
https://github.com/pulp/pulp_python/edit/main/index.md

# right edit-btn url
https://github.com/pulp/pulp_python/blob/main/docs/index.md
```