langref: add link to 0.6.0 version
langref: add link to 0.6.0 version

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