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/es.math.tanh.js

@@ -0,0 +1,16 @@
+'use strict';
+var $ = require('../internals/export');
+var expm1 = require('../internals/math-expm1');
+
+var exp = Math.exp;
+
+// `Math.tanh` method
+// https://tc39.es/ecma262/#sec-math.tanh
+$({ target: 'Math', stat: true }, {
+  tanh: function tanh(x) {
+    var n = +x;
+    var a = expm1(n);
+    var b = expm1(-n);
+    return a === Infinity ? 1 : b === Infinity ? -1 : (a - b) / (exp(n) + exp(-n));
+  }
+});