Add A practical git introduction

free-programming-books.md

@@ -880,6 +880,7 @@
 
 
 ### Git
+* [A practical git introduction](http://mrchlblng.me/2014/09/practical-git-introduction/)
 * [A Visual Git Reference](http://marklodato.github.io/visual-git-guide/index-en.html) - Mark Lodato
 * [Conversational Git](http://blog.anvard.org/conversational-git/)
 * [Git From The Bottom Up](http://ftp.newartisans.com/pub/git.from.bottom.up.pdf) (PDF)