Update SDL_GPUVulkanOptions documentation

Author: TheSniperFan

include/SDL3/SDL_gpu.h

@@ -2309,12 +2309,12 @@ extern SDL_DECLSPEC SDL_GPUDevice * SDLCALL SDL_CreateGPUDevice(
  * 
  * With the Vulkan renderer:
  *
- * - `SDL_PROP_GPU_DEVICE_CREATE_VULKAN_ADDITIONAL_FEATURES_POINTER`: pointer
- *   to a Vulkan structure to be appended to SDL's VkDeviceCreateInfo during
- *   device creation.
- *   This allows passing a list of VkPhysicalDeviceFeature structures to
- *   opt-into features aside from the minimal set SDL requires. It also allows
- *   requesting a higher API version and opting into extensions.
+ * - `SDL_PROP_GPU_DEVICE_CREATE_VULKAN_OPTIONS_POINTER`: pointer to an
+ *   SDL_GPUVulkanOptions structure to be processed during device creation.
+ *   This allows configuring a variety of Vulkan-specific options such as
+ *   increasing the API version and opting into extensions aside from the
+ *   minimal set SDL requires. The structure is NOT deep-copied. Make sure
+ *   that the pointer valid memory during window creation.
  * 
  * \param props the properties to use.
  * \returns a GPU context on success or NULL on failure; call SDL_GetError()
@@ -2352,17 +2352,26 @@ extern SDL_DECLSPEC SDL_GPUDevice * SDLCALL SDL_CreateGPUDeviceWithProperties(
 /**
  * A structure specifying additional options when using Vulkan.
  *
- * When no such structure is provided, SDL will use Vulkan API version 1.0 and a minimal set of features.
- * The feature list gets passed to the vkCreateInstance function and allows requesting additional
- * features.
+ * When no such structure is provided, SDL will use Vulkan API version 1.0 and
+ * a minimal set of features.
+ * The requested API version influences how the feature_list is processed by
+ * SDL. When requesting API version 1.0, the feature_list is ignored. Only the
+ * vulkan_10_phyisical_device_features and the extension lists are used. When
+ * requesting API version 1.1, the feature_list is scanned for feature
+ * structures introduced in Vulkan 1.1. When requesting Vulkan 1.2 or higher,
+ * the feature_list is additionally scanned for compound feature structs such
+ * as VkPhysicalDeviceVulkan11Features. The device and instance extension
+ * lists, as well as vulkan_10_physical_device_features, are always processed.
+ * The pointers inside this structure are NOT deep-copied. Make sure they are
+ * valid during window creation.
  * 
  * \since This struct is available since SDL 3.4.0.
  *
  */
 typedef struct SDL_GPUVulkanOptions
 {
     Uint32 vulkan_api_version; /**< The Vulkan API version to request for the instance. Use Vulkan's VK_MAKE_VERSION or VK_MAKE_API_VERSION. */
-    void *feature_list; /**< Pointer to the first element of a list of structs to be passed to device creation. */
+    void *feature_list; /**< Pointer to the first element of a chain of Vulkan feature structs. (Requires API version 1.1 or higher.)*/
 	void *vulkan_10_physical_device_features; /**< Pointer to a VkPhysicalDeviceFeatures struct to enable additional Vulkan 1.0 features. */
 	Uint32 device_extension_count; /**< Number of additional device extensions to require. */
 	const char **device_extension_names; /**< Pointer to a list of additional device extensions to require. */