switch to enum (#5223)

Author: RobinsAviary

examples/core/core_3d_camera_free.c

@@ -49,7 +49,7 @@ int main(void)
         //----------------------------------------------------------------------------------
         UpdateCamera(&camera, CAMERA_FREE);
 
-        if (IsKeyPressed('Z')) camera.target = (Vector3){ 0.0f, 0.0f, 0.0f };
+        if (IsKeyPressed(KEY_Z)) camera.target = (Vector3){ 0.0f, 0.0f, 0.0f };
         //----------------------------------------------------------------------------------
 
         // Draw