Added js regex cheatsheet (#4736)

* Added js regex cheatsheet

* Update free-programming-cheatsheets.md

Co-authored-by: Seth <seth@elypia.org>

Co-authored-by: Seth <seth@elypia.org>

free-programming-cheatsheets.md

@@ -36,6 +36,7 @@
 ### JavaScript
 
 * [JavaScript Cheatsheet](https://www.codecademy.com/learn/introduction-to-javascript/modules/learn-javascript-introduction/cheatsheet) - Codecademy (HTML)
+* [JavaScript Regex Cheatsheet](https://www.debuggex.com/cheatsheet/regex/javascript) - Debuggex (HTML)
 
 
 #### Vue.js
@@ -61,4 +62,3 @@
 ### Python
 
 * [Comprehensive Python Cheatsheet](https://gto76.github.io/python-cheatsheet) - Jure Šorn (HTML)
-