Add note about keyboard grab to WhatsNew.txt for 2.0.16
diff --git a/WhatsNew.txt b/WhatsNew.txt
index 5e1a4f8..69d2e74 100644
--- a/WhatsNew.txt
+++ b/WhatsNew.txt
@@ -8,6 +8,7 @@ General:
* Added SDL_FlashWindow() to get a user's attention
* Added SDL_GetAudioDeviceSpec() to get the preferred audio format of a device
* Added SDL_SetWindowAlwaysOnTop() to dynamically change the SDL_WINDOW_ALWAYS_ON_TOP flag for a window
+* Added SDL_SetWindowKeyboardGrab() to support grabbing the keyboard independently of the mouse
* Added SDL_SoftStretchLinear() to do bilinear scaling between 32-bit software surfaces
* Added SDL_UpdateNVTexture() to update streaming NV12/21 textures
* Added SDL_GameControllerSendEffect() and SDL_JoystickSendEffect() to allow sending custom trigger effects to the DualSense controller