Merge duplicated feeds

[sxzz]

Clear and concise description of the problem

• https://app.follow.is/share/feeds/41223694984583191
  • https://xlog.sxzz.moe/feed?format=xml with query version is introduced at very early stage of this app
• https://app.follow.is/share/feeds/61793761734436866
  • without query

Suggested solution

1. The author can verify both feeds and then merge them.
2. Alternatively, automatically merge based on <atom:link href="https://xlog.sxzz.moe/feed" rel="self" type="application/rss+xml"/>.

Alternative

No response

Additional context

No response

Validations

• [x] Check that there isn't already an issue that request the same feature to avoid creating a duplicate.
• [x] This issue is valid

[linear[bot]]

FOL-2080 Merge duplicated feeds