add chokidar and npm start

server.js

@@ -0,0 +1,26 @@
+const chokidar = require("chokidar");
+const handler = require("serve-handler");
+const http = require("http");
+
+const build = require("./build");
+
+chokidar
+  .watch(["style.css", "build.js", "docs", "fonts", "icon"], {
+    usePolling: true,
+  })
+  .on("change", (file) => {
+    console.log(
+      `[${new Date().toLocaleTimeString()}] ${file} changed -- rebuilding...`
+    );
+    build();
+  });
+
+const server = http.createServer((request, response) => {
+  return handler(request, response, {
+    public: "dist",
+  });
+});
+
+server.listen(3000, () => {
+  console.log("Running at http://localhost:3000");
+});