readme: update zig version

Author: kassane

README.md

@@ -12,7 +12,7 @@ Replacing the [CMake](https://cmake.org/) and [B2](https://www.bfgroup.xyz/b2/)
 
 ### Requirements
 
-- [zig](https://ziglang.org/download) v0.14.0 or master
+- [zig](https://ziglang.org/download) v0.15.1 or master
 
 ## How to use