docs.yml: fix changes from #230

i.e.  every step must define a `uses` or `run` key

.github/workflows/docs.yml

@@ -11,19 +11,23 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-      - uses: actions/checkout@v4
+        uses: actions/checkout@v4
+
+      - name: Set up git username and address
         run: |
           git config user.name github-actions[bot]
           git config user.email 41898282+github-actions[bot]@users.noreply.github.com
 
       - name: Install Python
-      - uses: actions/setup-python@v4
+        uses: actions/setup-python@v4
         with:
           python-version: '3.10'
 
+      - name: Set cache key
+        run: echo "cache_id=$(date --utc '+%V')" >> $GITHUB_ENV 
+
       - name: Handle cache
-      - run: echo "cache_id=$(date --utc '+%V')" >> $GITHUB_ENV 
-      - uses: actions/cache@v3
+        uses: actions/cache@v3
         with:
           key: mkdocs-material-${{ env.cache_id }}
           path: .cache
@@ -31,7 +35,7 @@ jobs:
             mkdocs-material-
 
       - name: Install MkDocs dependencies
-      - run: pip install -r requirements.docs.txt
+        run: pip install -r requirements.docs.txt
 
       - name: Deploy to GitHub Pages
-      - run: mkdocs gh-deploy --force
+        run: mkdocs gh-deploy --force