Desired Retention UI Overhaul

Ok, how about an idea suggested by Brayan: answer buttons that show interval lengths

The interval lengths above answer buttons would change instantly when desired retention is changed

More from Brayan:

put the fsrs parameters at the bottom of the FSRS section
and add some title to the “query input” (idk what is called the <input> form below the parameters)

No idea what to do about fuzz, though

  1. Display a range, like 14-18 days: “Why is there a range of intervals in deck options, but only a single interval in reality?”

  2. Just add fuzz to intervals, like ivl + fuzz_factor: “Why do intervals in deck options randomly jump around?”

  3. Don’t show fuzz: “Why do intervals in deck options do not jump around, but in reality they do?”