CI: publish docker image to Github Container Registry

Author: vasiliy-t

.github/workflows/main.yml

@@ -19,3 +19,16 @@ jobs:
 
       - name: Build
         run: make build
+
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Tag docker image
+        run: docker tag cert-manager-webhook-vkcloud:latest ghcr.io/vasiliy-t/cert-manager-webhook-vkcloud:latest
+
+      - name: Publish docker image to Github Container Registry
+        run: docker push ghcr.io/vasiliy-t/cert-manager-webhook-vkcloud:latest