fix(guide): simplify directory structure

guide/english/javascript/standard-objects/math/math-trunc/index.md

@@ -0,0 +1,20 @@
+---
+title: Math Trunc
+---
+## Math Trunc
+
+`Math.trunc()` is a method of the Math standard object that returns only the integer part of a given number by simply removing fractional units. This results in an overall rounding towards zero. Any input that is not a number will result in an output of NaN.
+
+Careful: This method is an ECMAScript 2015 (ES6) feature and thus is not supported by older browsers.
+
+### Examples
+```javascript
+Math.trunc(0.1)   //  0
+Math.trunc(1.3)   //  1
+Math.trunc(-0.9)  // -0
+Math.trunc(-1.5)  // -1
+Math.trunc('foo') // NaN
+```
+
+### More Information:
+* [MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/trunc)