Added GitHub workflow for greeting contributors (#540)

.github/workflows/greetings.yml

@@ -0,0 +1,21 @@
+name: Greetings
+
+on: [pull_request, issues]
+
+jobs:
+  greeting:
+    runs-on: 
+      - ubuntu-latest
+      - windows-latest
+      - macos-latest
+    steps:
+    - uses: actions/first-interaction@v1
+      with:
+        repo-token: ${{ secrets.GITHUB_TOKEN }}
+        issue-message: |
+          Hey @${{ github.actor }}, Welcome to the project Beautiify! 🎊 
+          Thanks for opening an issue! 🙌 Please wait for the issue to be assigned. Happy Coding!! ✨
+        pr-message: |
+          Hey @${{ github.actor }}, Welcome to the project Beautiify! 🎊 
+          Thanks for your contribution! Your effort makes this project better. Keep it up! 🙌
+          Please wait for the PR to be reviewed. Happy Coding!! ✨