Update README.md

added xcode generation in readme

Author: pythoneer

README.md

@@ -30,7 +30,12 @@ for cmake there is a CMakeLists.txt file -simply type (for all platforms):
 >$ cmake --build .
 ```
 
-for xcode there is an xcode project file
+for xcode you can generate a project by
+```
+>$ mkdir build
+>$ cd build
+>$ cmake -G Xcode ../XInputSimulator/
+```
 
 ####Status early Alpha
 2013-07-16: Linux, Mac and Win part with following functions