更新前端静态网页获取方式，放弃使用后端获取api

frontend/node_modules/core-js/modules/esnext.math.signbit.js

@@ -0,0 +1,12 @@
+'use strict';
+var $ = require('../internals/export');
+
+// `Math.signbit` method
+// https://github.com/tc39/proposal-Math.signbit
+$({ target: 'Math', stat: true, forced: true }, {
+  signbit: function signbit(x) {
+    var n = +x;
+    // eslint-disable-next-line no-self-compare -- NaN check
+    return n === n && n === 0 ? 1 / n === -Infinity : n < 0;
+  }
+});