static assets and favicon aren't cached by the browser

[obra]

Using datasette to solve some frustrating problems with our fulfillment provider today, I was surprised to see repeated requests for assets under /-/static and the favicon. While it won't likely be a huge performance bottleneck, I bet datasette would feel a bit zippier if you had Uvicorn serving up some caching-related headers telling the browser it was safe to cache static assets.

[simonw]

Come to think of it I've noticed that in the logs when it's running on my laptop, definitely worth fixing.