add note about `@tagName` for non-exhaustive enums
add note about `@tagName` for non-exhaustive enums

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