f add comment on whats going on

Author: TheBlueMatt

lightning-macros/src/lib.rs

@@ -278,6 +278,7 @@ pub fn drop_legacy_field_definition(expr: TokenStream) -> TokenStream {
 		if let syn::Expr::Macro(syn::ExprMacro { mac, .. }) = &field.expr {
 			let macro_name = mac.path.segments.last().unwrap().ident.to_string();
 			let is_init = macro_name == "_ignore_arg";
+			// Skip `field_name` and `:`, giving us just the type's group
 			let ty_tokens = mac.tokens.clone().into_iter().skip(2).next();
 			if let Some(proc_macro2::TokenTree::Group(group)) = ty_tokens {
 				let first_token = group.stream().into_iter().next();