Better RSS automation fetching!

Buttondown has now sent out over a million emails triggered purely through RSS! Whee!

To celebrate (well, not really to celebrate, but who's to say?):

• Buttondown checks RSS feeds around three times as fast now. Thanks, database optimizations!
• You can view the details of a feed and see when the last time it's been checked by Buttondown.
• And if you're super impatient, you can manually check it yourself by clicking the "Check for updates" button.