gpu: fixed formatting in docs.

include/SDL3/SDL_gpu.h

@@ -1917,7 +1917,7 @@ extern SDL_DECLSPEC SDL_GPUDevice *SDLCALL SDL_CreateGPUDevice(
  *   provide shaders for an NDA platform.
  * - `SDL_PROP_GPU_DEVICE_CREATE_SHADERS_SPIRV_BOOL`: The app is able to
  *   provide SPIR-V shaders if applicable.
- * - SDL_PROP_GPU_DEVICE_CREATE_SHADERS_DXBC_BOOL`: The app is able to provide
+ * - `SDL_PROP_GPU_DEVICE_CREATE_SHADERS_DXBC_BOOL`: The app is able to provide
  *   DXBC shaders if applicable
  *   `SDL_PROP_GPU_DEVICE_CREATE_SHADERS_DXIL_BOOL`: The app is able to
  *   provide DXIL shaders if applicable.