Sync SDL3 header -> wiki

SDL3/CategoryGamepad.md

@@ -31,6 +31,20 @@ the background, you should set the following hint before calling
 [SDL_Init](SDL_Init)():
 [SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS](SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS)
 
+Gamepads support various optional features such as rumble, color LEDs,
+touchpad, gyro, etc. The support for these features varies depending on the
+controller and OS support available. You can check for LED and rumble
+capabilities at runtime by calling
+[SDL_GetGamepadProperties](SDL_GetGamepadProperties)() and checking the
+various capability properties. You can check for touchpad by calling
+[SDL_GetNumGamepadTouchpads](SDL_GetNumGamepadTouchpads)() and check for
+gyro and accelerometer by calling
+[SDL_GamepadHasSensor](SDL_GamepadHasSensor)().
+
+By default SDL will try to use the most capable driver available, but you
+can tune which OS drivers to use with the various joystick hints in
+[SDL_hints](SDL_hints).h.
+
 <!-- END CATEGORY DOCUMENTATION -->
 
 ## Functions