[FEATURE REQUEST] Filter Feeds

[AaronKnowls]

Is your feature request related to a problem? Please describe.
Some feeds have many articles you don't care about, hence cluttering the app.

Describe the solution you'd like
Allowing 'block' and 'allow' filters per feed, so you can decide what articles will get through and which won't.

Describe alternatives you've considered
You can use filtering websites like shiftrss, but the time this takes, going there with every little change, it's just too too much.

Additional context
As sources of inspiration, android app Pluma RSS does a brilliant work with this. As also does Windows' QuiteRSS free and open source software.