docs: Conflict 발생 시와 PR/Issue 생성, 수정, 닫힘 이벤트에 대한 디스코드 알림 Actions 추가

.github/workflows/pr-issue-event-notifications.yml

@@ -0,0 +1,36 @@
+name: PR and Issue Event Notifications
+
+on:
+  pull_request:
+    types: [opened, edited, closed, synchronize]
+  issues:
+    types: [opened, edited, closed]
+
+jobs:
+  notify-discord:
+    runs-on: ubuntu-22.04
+
+    steps:
+    - name: Notify Discord on PR/Issue Events
+      uses: johnnyhuy/actions-discord-git-webhook@main
+      with:
+        webhook_url: ${{ secrets.DISCORD_WEBHOOK }}
+        args: |
+          👾 **GitHub 이벤트 발생** 👾
+          **Event**: ${{ github.event_name }}
+          **Action**: ${{ github.event.action }}
+          **Repository**: ${{ github.repository }}
+          **Actor**: ${{ github.actor }}
+          **Title**: ${{ github.event.pull_request.title || github.event.issue.title }}
+          **Link**: ${{ github.event.pull_request.html_url || github.event.issue.html_url }}
+          ---
+          🕒 **Timestamp**: ${{ github.event.pull_request.updated_at || github.event.issue.updated_at }}
+
+    - name: Notify Discord on Conflict in Pull Requests
+      if: ${{ github.event_name == 'pull_request' && github.event.action == 'synchronize' }}
+      run: |
+        curl -X POST -H "Content-Type: application/json" \
+          -d '{
+                "content": "🚨 **PR Conflict 발생** 🚨\n\n**PR Title**: '${{ github.event.pull_request.title }}'\n**Branch**: '${{ github.event.pull_request.head.ref }}'\n**URL**: '${{ github.event.pull_request.html_url }}'"
+              }' \
+          ${{ secrets.DISCORD_WEBHOOK }}