Revert postcss changes due to Hugo bug

Author: cchesser

.github/workflows/gh-pages.yml

@@ -22,6 +22,21 @@ jobs:
         with:
           hugo-version: '0.96.0'
           extended: true
+
+      - name: Setup Node
+        uses: actions/setup-node@v1
+        with:
+          node-version: '12.x'
+
+      - name: Cache dependencies
+        uses: actions/cache@v1
+        with:
+          path: ~/.npm
+          key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
+          restore-keys: |
+            ${{ runner.os }}-node-
+
+      - run: npm ci
       - run: hugo
         env:
           HUGO_ENV: production