added README

Author: johan0A

README.md

@@ -0,0 +1,24 @@
+# VulkanMemoryAllocator
+
+This is [VulkanMemoryAllocator](https://gpuopen.com/vulkan-memory-allocator/),
+packaged for the [Zig](https://ziglang.org/) build system.
+
+## how to use
+
+1. Add `zclay` to the dependency list in `build.zig.zon`: 
+
+```sh
+zig fetch --save git+https://github.com/johan0A/VulkanMemoryAllocator#v3.2.1
+```
+
+2. Config `build.zig`:
+
+```zig
+...
+const vma_dep = b.dependency("VulkanMemoryAllocator", .{
+    .target = target,
+    .optimize = optimize,
+});
+your_compilation.linkLibrary("vma", zclay_dep.artifact("VulkanMemoryAllocator"));
+...
+```