docs: note top level declarations are order-independent
docs: note top level declarations are order-independent

closes #1244

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