Adding Flask cheatsheet to compliment Python Web Framework resources (#7951)

* Adding Flask cheatsheet to compliment Python Web Framework resources

* Correcting spacing between newly added Flask sheet

* added additional space between sections

Co-authored-by: Targgus <jhenson@Johns-MacBook-Air.local>

more/free-programming-cheatsheets.md

@@ -32,6 +32,7 @@
 * [PHP](#php)
 * [Python](#python)
     * [Django](#django)
+    * [Flask](#flask)
 * [R](#r)
 * [Raspberry Pi](#raspberry-pi)
 * [Ruby](#ruby)
@@ -309,6 +310,11 @@
 * [(Python + Django) Cheatsheet](https://dev.to/ericchapman/my-beloved-django-cheat-sheet-2056) - Eric The Coder (HTML)
 
 
+#### Flask
+
+* [Flask Cheatsheet](https://www.codewithharry.com/blogpost/flask-cheatsheet/) - Code with Harry (HTML)
+
+
 ### R
 
 * [All RStudio cheatsheets resources](https://www.rstudio.com/resources/cheatsheets) - RStudio.com (HTML site with PDF links)