[guide] fix anchor tag in README.md

Currently, this anchor with missing end tag breaks rendering: https://github.com/airbnb/javascript/blob/5d1f4b9a49ee7def65343f5efccfcce7723b9b4b/README.md#arrays--from-iterable

Author: vsemozhetbyt

README.md

@@ -369,7 +369,7 @@ Other Style Guides
  const itemsCopy = [...items];
  ```
 
- <a name="arrays--from">
+ <a name="arrays--from"></a>
  <a name="arrays--from-iterable"></a><a name="4.4"></a>
  - [4.4](#arrays--from-iterable) To convert an iterable object to an array, use spreads `...` instead of [`Array.from`](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/from).