zig build system: implement custom command step
zig build system: implement custom command step

andrewrk/zig,Dimenus/zig,raulgrell/zig,raulgrell/zig,zig-lang/zig,raulgrell/zig,andrewrk/zig,zig-lang/zig,Dimenus/zig,raulgrell/zig,raulgrell/zig,Dimenus/zig,zig-lang/zig