Added 'Haskell and Yesod'

free-programming-books.md

@@ -373,6 +373,7 @@
 * [Wikibook Haskell](http://en.wikibooks.org/wiki/Haskell)
 * [Yet Another Haskell Tutorial](http://hal3.name/docs/daume02yaht.pdf) (PDF)
 * [Parallel and Concurrent Programming in Haskell](http://chimera.labs.oreilly.com/books/1230000000929)
+* [Haskell and Yesod](http://www.yesodweb.com/book-1.2)
 
 
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