Document CSS nodes and style classes

So app devs know they can use them.
11 jobs for css-drop-hdy in 20 minutes and 46 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Build
passed #246672
librem5
api-visibility

00:02:22

passed #246674
librem5
build-debian-clang

00:03:25

passed #246673
librem5
build-debian-gcc

00:02:38

passed #246675
librem5
build-fedora-gcc

00:03:06

 
  Test+Docs
passed #246676
librem5
build-gtkdoc

00:02:23

passed #246677
librem5
unit-test

00:02:22

43.2%
 
  Package
passed #246678
librem5
package-debian-buster

00:02:40

passed #246679
librem5:arm64
package-debian-buster:arm64

00:06:44

failed #246680
flatpak allowed to fail
package-flatpak

00:00:50

 
  Test Package
passed #246681
librem5
autopkgtest-debian-buster-package

00:02:29

passed #246682
librem5
lintian-debian-buster-package

00:00:54

 
Name Stage Failure
failed
package-flatpak Package
Committing stage finish to cache
Exporting sm.puri.Handy.Demo to repo
error: Writing content object: min-free-space-percent '3%' would be exceeded, at least 4.1?kB requested
Export failed: Child process exited with code 1
Uploading artifacts...
_build/meson-logs/meson-log.txt: found 1 matching files
WARNING: sm.puri.Handy.Demo-dev.flatpak: no matching files
Uploading artifacts to coordinator... ok
id=246680 responseStatus=201 Created token=3KpyBjLj
ERROR: Job failed: exit code 1