Use npm start to start the dev server

Author: sindresorhus

package.json

@@ -18,8 +18,8 @@
   ],
   "license": "MIT",
   "scripts": {
+    "start": "gatsby develop --open",
     "build": "gatsby build",
-    "develop": "gatsby develop",
     "format": "prettier --write 'src/**/*.js'",
     "test": "echo \"Error: no test specified\" && exit 1"
   },