add: release docker image with latest tag

.github/workflows/docker-image-ci.yml

@@ -15,7 +15,17 @@ jobs:
     - name: build
       if: github.event.deleted == false
       env:
-        DOCKER_IMAGE: ${{ github.repository }}:${{ github.sha }}
+        DOCKER_IMAGE: docker.pkg.github.com/${{ github.repository }}/action:latest
       run: |
         docker build . --file Dockerfile --tag ${DOCKER_IMAGE} ||
         (echo -e "\e[31m[${GITHUB_WORKFLOW}] failed to build\e[m" && exit 1)
+
+    - name: push latest image
+      if: success() && endsWith(github.ref, 'master')
+      env:
+        DOCKER_IMAGE: docker.pkg.github.com/${{ github.repository }}/action:latest
+        PKG_GITHUB_TOKEN: ${{ secrets.PKG_GITHUB_TOKEN }}
+      run: |
+        echo ${PKG_GITHUB_TOKEN} | docker login docker.pkg.github.com -u ${GITHUB_ACTOR} --password-stdin &&
+        docker push ${DOCKER_IMAGE} &&
+        docker logout