SDL: Add note about keyboard grab to WhatsNew.txt for 2.0.16

SDL Commits
1 
From f5bc58bf57f27455d34f3b09b7fe7e5c66dc5aad Mon Sep 17 00:00:00 2001
From: Cameron Gutman <[EMAIL REDACTED]>
Date: Tue, 3 Aug 2021 18:30:08 -0500
Subject: [PATCH] Add note about keyboard grab to WhatsNew.txt for 2.0.16

---
 WhatsNew.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/WhatsNew.txt b/WhatsNew.txt
index 5e1a4f839..69d2e7480 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