Merge branch 'dev' into feature-black

diff --cc .github/workflows/ci.yml
index 3798adf7c692c5ab54bfd41bbaa487a1b1986e9c,26c2ba0dc9c93b387f44153810a0f63f5e7bb216..b55d83128b759f5713628fcecc9bcc8501345272
--- 1/.github/workflows/ci.yml
--- 2/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@@ -142,35 -144,8 +142,8 @@@ jobs
            cd src/
            coveralls --service=github
  
-   frontend:
-     runs-on: ubuntu-20.04
-     steps:
-     -
-       name: Checkout
-       uses: actions/checkout@v2
-     -
-       uses: actions/setup-node@v2
-       with:
-         node-version: '16'
-     -
-       name: Configure version on dev branches
-       if: startsWith(github.ref, 'refs/heads/feature-') || github.ref == 'refs/heads/dev'
-       run: |
-         git_hash=$(git rev-parse --short "$GITHUB_SHA")
-         git_branch=${GITHUB_REF#refs/heads/}
-         sed -i -E "s/version: \"(.*)\"/version: \"${git_branch} ${git_hash}\"/g" src-ui/src/environments/environment.prod.ts
-     -
-       name: Build frontend
-       run: ./compile-frontend.sh
-     -
-       name: Upload artifact
-       uses: actions/upload-artifact@v2
-       with:
-         name: frontend-compiled
-         path: src/documents/static/frontend/
- 
    build-release:
-     needs: [frontend, documentation, tests, codeformatting, codestyle]
 -    needs: [build-docker-image, documentation, tests, whitespace, codestyle]
++    needs: [build-docker-image, documentation, tests, codeformatting, codestyle]
      runs-on: ubuntu-20.04
      steps:
        -
@@@ -281,7 -256,7 +254,7 @@@
    build-docker-image:
      if: github.event_name == 'push' && (startsWith(github.ref, 'refs/heads/feature-') || github.ref == 'refs/heads/dev' || startsWith(github.ref, 'refs/tags/ng-'))
      runs-on: ubuntu-latest
-     needs: [frontend, tests, codeformatting, codestyle]
 -    needs: [tests, whitespace, codestyle]
++    needs: [tests, codeformatting, codestyle]
      steps:
        -
          name: Prepare

diff --cc CONTRIBUTING.md
Simple merge

diff --cc docs/extending.rst
Simple merge