Add dev script

app.js

@@ -0,0 +1,14 @@
+var serveStatic = require('serve-static')
+var http = require('http')
+var fs = require('fs')
+
+var notfound = fs.readFileSync('404.dev.html')
+
+http.createServer(function (req, res) {
+  serveStatic('.')(req, res, function () {
+    res.writeHead(404, { 'Content-Type': 'text/html' })
+    res.end(notfound)
+  })
+}).listen(3000)
+
+console.log(`\nListening at http://localhost:3000\n`)