Filter random notes

[mammuth]

Random notes could be filtered by words and phrases (including as well as excluding them).

Maybe django-filters could be used for that purpose (thinking about reusing it for the API).

Maybe it's also filterable by book. In this case we probably need a "link generator" view which generates the URL with all those filteres applied as GET parameters.

[mammuth]

I'd consider this low prio - I don't know how many people use the random quotes feature (https://reading-notes.com/en/clippings/random-fullscreen?refresh=60), but I'd expect not too many.