message: Add jrvanwhys description for the main attribute as doc
diff: @@ -9,6 +9,13 @@ use syn;
  use syn::Error;
  use syn::ItemFn;
  +/// Procedural attribute macro. This is meant to be applied to a binary's async
  +/// `main()`, transforming into a function that returns a type acceptable for
  +/// `main()`. In other words, this will not compile with libtock-rs:
  +/// async fn main() {}
  +/// and this will:
  +/// #[async_main]
  +/// async fn main() {}
  #[proc_macro_attribute]
  pub fn libtock_main(_: TokenStream, input: TokenStream) -> TokenStream {
  generate_main_wrapped(input.into()).into()
  