Fix link to Edmonds chocolate cake example recipe

Author: paultcochrane

git/git_on_your_own.tex

@@ -86,7 +86,7 @@ \section{Example project: a kiwi café}
 
 \begin{frame}[fragile]{Kiwi café: a first recipe}
     Fill the file with this text
-    (\href{https://github.com/paultcochrane/git_course/git/examples/edmonds-chocolate-cake.md}{\beamerbutton{link}}):
+    (\href{https://github.com/paultcochrane/git_course/blob/master/git/examples/edmonds-chocolate-cake.md}{\beamerbutton{link}}):
     \inputminted[fontsize=\tiny]{markdown}{examples/edmonds-chocolate-cake.md}
     {\footnotesize \emph{Edmonds Cookery Book}, 51st De Luxe Edition, 2003.}
 \end{frame}