chore: add image workflow

.github/workflows/publish.yml

@@ -0,0 +1,35 @@
+name: publish
+
+on:
+  release:
+    types:
+      - published
+
+jobs:
+  image:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout project
+        uses: actions/[email protected]
+
+      - name: Authenticate with Quay.io
+        uses: docker/[email protected]
+        with:
+          registry: quay.io
+          username: ${{ secrets.QUAY_USERNAME }}
+          password: ${{ secrets.QUAY_ROBOT_TOKEN }}
+
+      - name: Generate image tag
+        id: image_tag
+        run: |
+          echo tag=$(echo ${{ github.event.release.tag_name }} | sed 's/^v//') >> $GITHUB_OUTPUT
+
+      - name: Build image
+        uses: docker/[email protected]
+        with:
+          context: .
+          file: Dockerfile
+          push: true
+          tags: |
+            quay.io/tadas/rally-exporter:latest
+            quay.io/tadas/rally-exporter:${{ steps.image_tag.outputs.tag }}