docs: fixed typo RegEx > RegExp

Author: niftylettuce

README.md

@@ -111,7 +111,7 @@ Assuming you are using [browserify][], [webpack][], [rollup][], or another bundl
 | `ipv4`         | Boolean | `true`                                                       | Match against IPv4 URL's.                                                                                                                                                                                                                                                                                                                                      |   |
 | `ipv6`         | Boolean | `true`                                                       | Match against IPv6 URL's.                                                                                                                                                                                                                                                                                                                                      |   |
 | `tlds`         | Array   | [tlds](https://github.com/stephenmathieson/node-tlds#readme) | Match against a specific list of tlds, or the default list provided by [tlds](https://github.com/stephenmathieson/node-tlds#readme).                                                                                                                                                                                                                           |   |
-| `returnString` | Boolean | `false`                                                      | Return the RegEx as a String instead of a `RegExp` (useful for custom logic, such as we did with [Spam Scanner][spam-scanner]).                                                                                                                                                                                                                                |   |
+| `returnString` | Boolean | `false`                                                      | Return the RegExp as a String instead of a `RegExp` (useful for custom logic, such as we did with [Spam Scanner][spam-scanner]).                                                                                                                                                                                                                               |   |
 
 
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