Add GitHub Actions deploy workflow

Automatically deploys to exe.dev VM on push to master.
Uses SSH to pull latest code and rebuild Docker container.

Co-authored-by: Shelley <shelley@exe.dev>

.github/workflows/deploy.yml

@@ -0,0 +1,17 @@
+name: Deploy to exe.dev
+
+on:
+  push:
+    branches: [master]
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Deploy via SSH
+        uses: appleboy/ssh-action@v1
+        with:
+          host: love-tin.exe.xyz
+          username: exedev
+          key: ${{ secrets.DEPLOY_SSH_KEY }}
+          script: /home/exedev/deploy.sh