[docs] CD workflow 추가

Author: JayongLee

.github/workflows/main.yml

@@ -0,0 +1,35 @@
+name: CD to EC2
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v3
+
+      - name: Add SSH key
+        run: |
+          mkdir -p ~/.ssh
+          echo "${{ secrets.EC2_SSH_KEY }}" > ~/.ssh/id_rsa
+          chmod 600 ~/.ssh/id_rsa
+          ssh-keyscan -H ${{ secrets.EC2_HOST }} >> ~/.ssh/known_hosts
+
+      - name: Deploy with SSH
+        run: |
+          ssh ${{ secrets.EC2_USER }}@${{ secrets.EC2_HOST }} << 'EOF'
+            set -e
+            cd ${{ secrets.EC2_PATH }}
+
+            # Git pull or clone if not yet
+            if [ ! -d ".git" ]; then
+              git clone https://github.com/${{ github.repository }} .
+            else
+              git pull origin main
+            fi
+          EOF