chore: use concurrently in start script

Author: nodkz

package.json

@@ -74,7 +74,7 @@
     "build": "npm run buildSchema",
     "seed": "./node_modules/.bin/ts-node ./scripts/seed.ts",
     "buildSchema": "./node_modules/.bin/ts-node ./scripts/buildSchema.ts",
-    "start": "npm run seed && ts-node index.ts",
+    "start": "concurrently \"npm:seed\" \"ts-node index.ts\"",
     "dev": "ts-node-dev index.ts",
     "watch": "jest --watch",
     "coverage": "jest --coverage --maxWorkers 2",