the path to the mirror settings have changed, and mention the caveat
about the homepage. alo filed an issue to improve *that*.

service/documentation.md

@@ -186,7 +186,7 @@ into a separate project.
     if you do not plan to host other source code specific to that
     project there. we'll call this the "wiki replica" in either case
 
- 3. in the wiki replica, head for the **Settings: Mirroring
+ 3. in the wiki replica, head for the **Settings / Repository / Mirroring
     repositories** section and fill in the details for the wiki HTTPS
     clone URL:
 
@@ -222,6 +222,14 @@ from the wiki to the replica. But considering only a limited set of
 users have access to the wiki in the first place, this shouldn't be a
 problem as long as everyone pushes to the replica.
 
+Another major caveat is that git repositories and wikis have a
+different "home page". In repositories, the `README.*` or `index.*`
+files get rendered in any directory (including the frontpage). But in
+the wiki, it's the `home.md` page and [it is not possible to change
+this](https://gitlab.com/gitlab-org/gitlab/-/issues/19842). It's also [not possible to change the landing page on
+repositories either](https://gitlab.com/gitlab-org/gitlab/-/issues/20754), a compromise would be to [preview the wiki
+home page correctly in repositories](https://gitlab.com/gitlab-org/gitlab/-/issues/432344).
+
 ## Pager playbook
 
 ### Wiki unavailable