Ability to disable a source without deleting it

[tuxiqae]

Describe the solution you'd like A button under the Sources tab in the settings which will allow to toggle on and off selected sources without the need to delete them. When a source is disabled all its articles will be removed and no new ones will be shown.

Thanks!

[boikyeet]

I asked for something similar in #336. Some sources like news sites update very frequently and it would be nice being able to disable them temporarily so that you could see the sources with less frequent updates like personal blogs and such