Add Malven's flexbox & grid cheatsheets (#5446)

* Add Malven's Flexbox & Grid cheatsheets

- Add "FLEX: A simple visual cheatsheet for flexbox" https://flexbox.malven.co
- Add "GRID: A simple visual cheatsheet for CSS Grid Layout" https://grid.malven.co

* Add Malven's Flexbox & Grid cheatsheets

- CI/CD: Restore new line at end of javascript section

more/free-programming-cheatsheets.md

@@ -66,6 +66,8 @@
 * [CSS CheatSheet](https://htmlcheatsheet.com/css/) (HTML)
 * [CSS Flexbox Cheatsheet](https://css-tricks.com/snippets/css/a-guide-to-flexbox/) - Chris Coyier (HTML)
 * [CSS Grid Cheatsheet](https://css-tricks.com/snippets/css/complete-guide-grid/) - Chris House (HTML)
+* [FLEX: A simple visual cheatsheet for flexbox](https://flexbox.malven.co) - Chris Malven (HTML)
+* [GRID: A simple visual cheatsheet for CSS Grid Layout](https://grid.malven.co) - Chris Malven (HTML)
 * [HTML CheatSheet](https://htmlcheatsheet.com) (HTML)