Add tracking to channels (include from all)

[pstuifzand]

In the original version I had a filter that added all items matching a regex to a channel. In the settings page there should be a place to add keywords to a channel (even if it has no feeds) and gather all items matching those keywords (or perhaps) regex.

(Originally published at: https://p83.nl/p/783)

[pstuifzand]

Completed.