updated theme zips and their hashes in theme.json except for chan and dark chan themes
chan.zip and dark_chan.zip updates omitted because of filesize limitations:
```
~/src/stack-theme-selector-server/data/themes$ git push
Enumerating objects: 29, done.
Counting objects: 100% (29/29), done.
Delta compression using up to 16 threads
Compressing objects: 100% (15/15), done.
Writing objects: 100% (15/15), 19.87 MiB | 1.03 MiB/s, done.
Total 15 (delta 11), reused 0 (delta 0)
remote: Resolving deltas: 100% (11/11), completed with 7 local objects.
remote: error: Trace: e1b22f30bb4537608d11904078c85aa7590f679e080f0a2ab566be57badd5837
remote: error: See https://gh.io/lfs for more information.
remote: error: File data/themes/dark_chan.zip is 108.89 MB; this exceeds GitHub's file size limit of 100.00 MB
remote: error: File data/themes/chan.zip is 109.07 MB; this exceeds GitHub's file size limit of 100.00 MB
remote: error: GH001: Large files detected. You may want to try Git Large File Storage - https://git-lfs.github.com.To github.com:cypherstack/stack-theme-selector-server
! [remote rejected] temp -> temp (pre-receive hook declined)
```
added images to each theme and their `theme.json`s
and ignored non-zip files in working theme data dir for QoL
