deploy: add pm2 ecosystem file

ecosystem.config.cjs

@@ -0,0 +1,15 @@
+module.exports = {
+  apps: [{
+    name: 's22-poll',
+    script: './server/server.js',
+    instances: 1,
+    exec_mode: 'fork',
+    env: {
+      NODE_ENV: 'development'
+    },
+    env_production: {
+      NODE_ENV: 'production',
+      PORT: 3001
+    }
+  }]
+};