Harden a bit, update some sections, add a README section

.github/workflows/container-build.yaml

@@ -17,7 +17,6 @@ env:
 jobs:
   build-and-push-image:
     runs-on: ubuntu-latest
-    continue-on-error: true
     permissions:
       contents: read
       packages: write
@@ -32,18 +31,19 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0
 
       - name: Set up QEMU
-        uses: docker/setup-qemu-action@v2
+        uses: docker/setup-qemu-action@v3
 
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v2
+        uses: docker/setup-buildx-action@v3
 
       - name: Login to Container registry
-        uses: docker/login-action@v2
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v3
         with:
           registry: ${{ env.REGISTRY }}
           username: ${{ github.actor }}
@@ -51,7 +51,7 @@ jobs:
 
       - name: Docker meta
         id: meta
-        uses: docker/metadata-action@v4
+        uses: docker/metadata-action@v5
         with:
           images: |
             ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
@@ -67,9 +67,9 @@ jobs:
             suffix=${{ matrix.suffix }}
 
       - name: Build and push
-        uses: docker/build-push-action@v4
+        uses: docker/build-push-action@v6
         with:
-          platforms: linux/amd64,linux/386,linux/arm64,linux/arm/v7,linux/arm/v6
+          platforms: linux/amd64,linux/arm64,linux/arm/v7
           context: .
           file: ${{ matrix.container }}
           push: ${{ github.event_name != 'pull_request' }}