Fix ordering

free-programming-playgrounds.md

@@ -8,7 +8,7 @@
 * [PHP](#php)
 * [Python](#python)
 * [Ruby](#ruby)
-* [sql](#sql)
+* [SQL](#sql)
 
 
 ### Angular
@@ -16,11 +16,6 @@
 * [Plunker](http://plnkr.co)
 
 
-### FlexBox
-
-* [Echoplex](http://the-echoplex.net/flexyboxes/)
-
-
 ### CSS
 
 * [CodePen](http://codepen.io)
@@ -29,6 +24,11 @@
 * [Dabblet](http://dabblet.com)
 
 
+### FlexBox
+
+* [Echoplex](http://the-echoplex.net/flexyboxes/)
+
+
 ### JavaScript
 
 * [CodePen](http://codepen.io)