更新前端静态网页获取方式，放弃使用后端获取api

frontend/node_modules/underscore/cjs/toString.js

@@ -0,0 +1,9 @@
+var value = require('./value.js');
+
+// Provide an unwrapping proxy for automatic string coercion in engine
+// operations such as JSON stringification.
+function toString(wrapper) {
+  return String(value(wrapper));
+}
+
+module.exports = toString;