pin used actions

plus some reordering and harmonization across files

.github/workflows/documentation-build.yml

@@ -1,4 +1,4 @@
-name: Generate Docs
+name: Build Documentation
 
 permissions:
   contents: read    # write permission to the destination repo come from 'deploy_key'
@@ -24,12 +24,12 @@ env:
 
 jobs:
   docs:
-    name: Doxygen
-    runs-on: ubuntu-latest
+    name: "Doxygen"
+    runs-on: ubuntu-latest    # https://github.com/actions/runner-images#available-images
 
     steps:
       - name: "Checkout"
-        uses: actions/checkout@v7
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           submodules: recursive
 
@@ -42,7 +42,7 @@ jobs:
       - name: "Install Doxygen"
         uses: ssciwr/doxygen-install@v2
         with:
-          version: "1.18.0"
+          version: "1.18.0"    # https://www.doxygen.nl/manual/changelog.html
 
       - name: "Update Doxygen Configuration"
         shell: bash
@@ -65,7 +65,7 @@ jobs:
 
       - name: "Deploy to cockatrice.github.io/docs"
         if: github.event_name == 'release' || github.event_name == 'workflow_dispatch'
-        uses: peaceiris/actions-gh-pages@v4
+        uses: peaceiris/actions-gh-pages@84c30a85c19949d7eee79c4ff27748b70285e453 # v4.1.0
         with:
           deploy_key: ${{ secrets.DOCS_DEPLOY_KEY }}
           destination_dir: docs    # docs will be available at https://cockatrice.github.io/docs/