docs: Update documentation

[fsbraun]

Description

This PR updates some elements of the documentation. It currently is a draft. Please add to this discussion if you are missing
documentation.

Changes

• Use of furo theme as it is standard with django CMS packages
• Update of the release notes
• Some syntax fixes

Checklist

• I have opened this pull request against master
• I have added or modified the tests when changing logic
• I have followed the conventional commits guidelines to add meaningful information into the changelog
• I have read the contribution guidelines and I have joined #workgroup-pr-review on
  Slack to find a “pr review buddy” who is going to review my pull request.

[codecov]

Codecov Report

Patch and project coverage have no change.

Comparison is base (58c141c) 90.93% compared to head (03c60a4) 90.93%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #351   +/-   ##
=======================================
  Coverage   90.93%   90.93%           
=======================================
  Files          72       72           
  Lines        2536     2536           
  Branches      357      357           
=======================================
  Hits         2306     2306           
  Misses        170      170           
  Partials       60       60           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[marksweb]

Could add spell checking as well perhaps, but otherwise it looks good 👍

[fsbraun]

Already added spell checking in the last PR... 😃