Updated doxygen config with Vulkan plugin documentation

Documentation/Doxygen/Native.doxyconfig

@@ -794,7 +794,8 @@ INPUT                  = ../../Source/BansheeUtility/Include \
                          ../Manuals/Native \
                          ../../Source/BansheeFMOD/Include \
                          ../../Source/BansheeOpenAudio/Include \
-                         ../Manuals/Native/User
+                         ../Manuals/Native/User \
+                         ../../Source/BansheeVulkanRenderAPI
 
 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding. Doxygen uses