Support multiple tags per feed

Checklist

[X] I have used the search function for OPEN issues to see if someone else has already submitted the same feature request.
[X] I have also used the search function for CLOSED issues to see if the feature was already implemented and is just waiting to be released, or if the feature was rejected.
[X] I will describe the problem with as much detail as possible.
[X] This request contains only one single feature, not a list of multiple (related) features.

App version

2.6.33

Where did you get the app from

F-Droid

Feature or improvement you want

If possible please add the option to add an rss source to a separate Favourite folder/tag/label like in Inoreader. This won't remove the rss source from its original folder/tag.

Why should this be added?

If you have 100s of RSS sources and less time, it would be easy to just scroll through your favourite feeds grouped in a folder, tag.

Screenshots / Drawings / Technical details

No response

spacecowboy / Feeder

Support multiple tags per feed #409