Minor fix in README.md.
# Vulkan Memory Allocator
-This is a README file for Vulkan Memory Allocator library and accompanying sample application.
+Easy to integrate Vulkan memory allocation library.
**Documentation:** See [Vulkan Memory Allocator](https://gpuopen-librariesandsdks.github.io/VulkanMemoryAllocator/html/) (generated from Doxygen-style comments in [src/vk_mem_alloc.h](src/vk_mem_alloc.h)).
