Is your feature request related to a problem? Please describe.
Currently, all feeds refresh at the same time — that is, when a refresh is triggered, all feeds are quickly queried sequentially. This can lead to rate limiting issues. I have seen these rate limits with YouTube and Spotify so far.

Describe the solution you’d like
I propose the ability to add a minimum polling rates for feeds. There's a couple types:

• Per-feed: Before the feed is polled, a delay occurs.
  • This allows the user to specify a delay for a specific feed that may be within a category that doesn't need a delay between all feeds.
• Per-category: Set a delay for the group so that there is a delay that occurs between every feed in the group.
  • For example: say one has a collection of YouTube feeds in one category. Setting this minimum delay would require a delay to occur between each YouTube feed in the category.

Describe alternatives you’ve considered
None.

Additional context
None.