added Windows Phone 8 Development Succinctly

added free ebook "Windows Phone 8 Development Succinctly" from syncfusion.

link: http://www.syncfusion.com/resources/techportal/ebooks/windowsphone8

free-programming-books.md

@@ -1624,6 +1624,7 @@ See also [LaTeX](#latex)
 * [Developing An Advanced Windows Phone 7.5 App That Connects To The Cloud](http://coolthingoftheday.blogspot.co.uk/2012/05/free-ebook-guidance-advanced-windows.html)
 * [Programming Windows Phone 7](http://blogs.msdn.com/b/microsoft_press/archive/2010/10/28/free-ebook-programming-windows-phone-7-by-charles-petzold.aspx)
 * [Windows Phone Programming Blue Book](http://www.robmiles.com/c-yellow-book/)
+* [Windows Phone 8 Development Succinctly](http://www.syncfusion.com/resources/techportal/ebooks/windowsphone8)
 
 
 ###Workflow