Support multiple classes in a single literal in classes! macros

[therustmonk]

I like all the improvements of 0.18.0. Thanks to EVERYONE who did that 💘

During porting my super huge rillrate project to the Yew 0.18.0 I've found that I have to split a lot of classes to separate literals, but before was possible to use multiple classes in a string like:

html! {
    <div class=("many so-many bootstrap classes", option) />
}

With 0.18.0 I have to split them all or use the following workaround:

html! {
    <div class=classes!(Classes::from("many so-many bootstrap classes"), option) />
}

I guess it's not so effective and at least it's not so pretty.

How about to allow to parse multiple classes during compilation of to add Classes::from workaround to that?
Or maybe I missed some features? 😃

[ranile]

You can use macro like:

html! {
    <div class=classes!("many", "so-many", "bootstrap", "classes", option) />
}

I think the macro should take each class individually, instead of allowing multiple classes to be passed as one.