Merge branch 'category-browser-paging' into 'master'

Add pagination to app category detail pages

Add pagination to the app category detail pages as suggested in !52.

This could in sum be a solution for the issues #18 and #5.

See merge request !58

closes fdroid-website#479
closes #5
closes #18
2 jobs for master in 2 minutes and 7 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
passed #855651059
debian_buster

00:00:54

passed #855651058
ruby_latest

00:02:07