Update readme with Build Notes section (#117)

README.md

@@ -648,6 +648,18 @@ to this folder by adding a `Web.config` file.
     </configuration>
 ```
 
+### Build Notes
+
+The i18n project at present targets Visual Studio 2012 and requires Visual Studio 2012 SDK libraries
+installed to build.
+
+To build the project in Visual Studio 2013:
+1. install the Visual Studio 2013 SDK is not already installed
+2. upgrade the i18n project to 2013
+3. remove the reference to Microsoft.VisualStudio.Shell.11 and replace it with a reference to Microsoft.VisualStudio.Shell.12.
+
+See [Issue #117](https://github.com/turquoiseowl/i18n/issues/117#issuecomment-57867637) for more information on building with VS 2013.
+
 ### Contributing
 
 There's lot of room for further enhancements and features to this library, and you are encouraged to fork it and