Fix documentation to state that VmaAllocatorCreateInfo::instance is now required

Compatibility breaking!
Closes #107

src/vk_mem_alloc.h

diff --git a/src/vk_mem_alloc.h b/src/vk_mem_alloc.h
index ab0bb8c..3c95d8b 100644
--- a/src/vk_mem_alloc.h
+++ b/src/vk_mem_alloc.h
@@ -2214,10 +2214,9 @@
     creation of the allocator object fails with `VK_ERROR_FEATURE_NOT_PRESENT`.

     */

     const VmaRecordSettings* pRecordSettings;

-    /** \brief Optional handle to Vulkan instance object.

+    /** \brief Handle to Vulkan instance object.

 

-    Optional, can be null. Must be set if #VMA_ALLOCATOR_CREATE_EXT_MEMORY_BUDGET_BIT flas is used

-    or if `vulkanApiVersion >= VK_MAKE_VERSION(1, 1, 0)`.

+    Starting from version 3.0.0 this member is no longer optional, it must be set!

     */

     VkInstance instance;

     /** \brief Optional. The highest version of Vulkan that the application is designed to use.

@@ -15085,7 +15084,7 @@
         VMA_ASSERT(VMA_DEBUG_MARGIN % sizeof(uint32_t) == 0);

     }

 

-    VMA_ASSERT(pCreateInfo->physicalDevice && pCreateInfo->device);

+    VMA_ASSERT(pCreateInfo->physicalDevice && pCreateInfo->device && pCreateInfo->instance);

 

     if(m_VulkanApiVersion < VK_MAKE_VERSION(1, 1, 0))

     {