github: Add GitHub action to greet first time contributors

.github/workflows/greet_first_time_contributor.yml

@@ -0,0 +1,50 @@
+name: Greet first time contributor
+
+on:
+  issues:
+    types: [opened]
+  pull_request:
+    types: [opened, closed]
+
+jobs:
+  check_for_first_interaction:
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v3
+      - uses: zephyrproject-rtos/[email protected]
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+
+          issue-message: >
+            Hi @${{github.event.issue.user.login}}! We appreciate you submitting your first issue
+            for our open-source project. 🌟
+
+
+            Even though I'm a bot, I can assure you that the whole community is genuinely grateful
+            for your time and effort. 🤖💙
+
+          pr-opened-message: >
+            Hello @${{ github.event.pull_request.user.login }}, and thank you very much for your
+            first pull request to the Zephyr project!
+
+
+            A project maintainer just triggered our CI pipeline to run it against your PR and
+            ensure it's compliant and doesn't cause any issues. You might want to take this
+            opportunity to review the project's [Contributor
+            Expectations](https://docs.zephyrproject.org/latest/contribute/contributor_expectations.html)
+            and make any updates to your pull request if necessary. 😊
+
+          pr-merged-message: >
+            Hi @${{ github.event.pull_request.user.login }}!
+
+            Congratulations on getting your very first Zephyr pull request merged 🎉🥳. This is a
+            fantastic achievement, and we're thrilled to have you as part of our community!
+
+
+            To celebrate this milestone and showcase your contribution, we'd love to award you the
+            Zephyr Technical Contributor badge. If you're interested, please claim your badge by
+            filling out this form: [Claim Your Zephyr Badge](https://forms.gle/oCw9iAPLhUsHTapc8).
+
+
+            Thank you for your valuable input, and we look forward to seeing more of your
+            contributions in the future! 🪁