ci: add Slack notification for new issues

Author: jpr5

.github/workflows/notify-issue.yml

@@ -0,0 +1,18 @@
+name: Issue Notification
+on:
+  issues:
+    types: [opened]
+jobs:
+  notify:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Notify Slack
+        if: ${{ secrets.SLACK_WEBHOOK != '' }}
+        run: |
+          TITLE="${{ github.event.issue.title }}"
+          URL="${{ github.event.issue.html_url }}"
+          AUTHOR="${{ github.event.issue.user.login }}"
+          NUM="${{ github.event.issue.number }}"
+          curl -sf -X POST "${{ secrets.SLACK_WEBHOOK }}" \
+            -H "Content-Type: application/json" \
+            -d "{\"text\": \"🐛 New issue #${NUM} on aimock by *${AUTHOR}*: <${URL}|${TITLE}>\"}"