Bind media volume on runner container

so that the built site can be copied to the document root for the site

.forgejo/workflows/build-eleventy.yaml

@@ -10,6 +10,8 @@ jobs:
     runs-on: docker
     container:
       image: node:18
+      volumes:
+        - /media/Media:/media/Media
 
     steps:
       - name: Checkout code
@@ -24,6 +26,11 @@ jobs:
       - name: Build Eleventy site
         run: npm run build
 
+      - name: Debugging step
+        run: |
+          echo '/media: `ls /media`'
+          echo '/media/Media: `ls /media/Media`'
+
       - name: Move built site
         run: |
           if [ "${{ github.ref }}" == "refs/heads/main" ]; then