GitHubCI: run prettier to check YML style (#101)

.github/workflows/CI.yml

@@ -94,8 +94,8 @@ jobs:
   sanity-check:
     name: Sanity check
     needs:
-    - file-conventions-tests
-    - commitlint-plugins-tests
+      - file-conventions-tests
+      - commitlint-plugins-tests
     runs-on: ubuntu-22.04
     container:
       image: "ubuntu:22.04"
@@ -150,9 +150,10 @@ jobs:
         # We need this step so we can change the files using `npx prettier --write` in the next step.
         # Otherwise we get permission denied error in the CI.
         run: sudo chmod 777 -R .
-      - name: Run "prettier" to check the style of our TypeScript code
+      - name: Run "prettier" to check the style of our TypeScript and YML code
         run: |
           sudo npx prettier --quote-props=consistent --write './**/*.ts'
+          sudo npx prettier --quote-props=consistent --write './**/*.yml'
           # Since we changed file modes in the previous step we need the following command to
           # make git ignore mode changes in files and doesn't include them in the git diff command.
           git config core.fileMode false
@@ -166,4 +167,3 @@ jobs:
           dotnet tool install fantomless-tool --version 4.7.997-prerelease
           dotnet fantomless --recurse .
           git diff --exit-code
-