This was originally taken out of T407654, which we are breaking down into sub-tasks.
- The config option MFRSSFeedLink is provided but never enabled in production. We should drop it.
- The config option is always MFEnableManifest and doesn't need to be configurable. We should drop it.
QA:
- https://en.wikipedia.org/w/index.php?title=Paris&mobileaction=toggle_view_mobile page source does not contain <link rel="alternate" type="application/atom+xml"
- https://en.wikipedia.org/w/index.php?title=Paris&mobileaction=toggle_view_mobile page source contains <link rel="manifest"