ci: create greetings.yml

.github/workflows/greetings.yml

@@ -0,0 +1,16 @@
+name: Greetings
+
+on: [pull_request_target]
+
+jobs:
+  greeting:
+    runs-on: ubuntu-latest
+    permissions:
+      issues: write
+      pull-requests: write
+    steps:
+    - uses: actions/first-interaction@v1
+      with:
+        repo-token: ${{ secrets.GITHUB_TOKEN }}
+        #issue-message: "Message that will be displayed on users' first issue"
+        pr-message: "你好 @${{ github.actor }}，感谢提交PR！\n我们会尽早审核回应~😊"