Sync SDL3 wiki -> header

[ci skip]

(cherry picked from commit 0246598d6241c25ddb5c8311fe95318ca8511956)

include/SDL3/SDL_main.h

@@ -667,9 +667,11 @@ extern SDL_DECLSPEC void SDLCALL SDL_UnregisterApp(void);
  * This should be called from an event watch in response to an
  * `SDL_EVENT_DID_ENTER_BACKGROUND` event.
  *
- * When using SDL_Render or SDL_GPU, your event watch should be added _after_
- * creating the `SDL_Renderer` or `SDL_GPUDevice`; this allows the timing of
- * the D3D12 command queue suspension to execute in the correct order.
+ * When using SDL_Render, your event watch should be added _after_ creating
+ * the `SDL_Renderer`; this allows the timing of the D3D12 command queue
+ * suspension to execute in the correct order.
+ *
+ * When using SDL_GPU, this should be called after calling SDL_GDKSuspendGPU.
  *
  * If you're writing your own D3D12 renderer, this should be called after
  * calling `ID3D12CommandQueue::SuspendX`.