Add slack messsaging job

Author: philipluk

.github/workflows/node_js_containers.yml

@@ -26,6 +26,12 @@ jobs:
           entrypoint: ./script.sh
           args: "Some string"
 
+      # Send a Slack message
+      - name: send a slack message
+        uses: docker://technosophos/slack-notify
+        env:
+          SLACK_WEBHOOK: ${{ secrets.SLACK_WEBHOOK }}
+          SLACK_MESSAGE: "Hello slack" 
 
   node-docker:
     runs-on: ubuntu-latest