Very slight breakage by Rust 2021 Edition

[SorteKanin]

Rust 2021 has reserved the prefix#identifier syntax. This causes the following to fail to compile

use maud::html;

fn main() {
    let markup = html! {
        div#my-id {}
    };
}

because div#my-id uses the reserved syntax.

The easy fix is just to add a space between the tokens: div #my-id. Not very significant but the examples on the website should perhaps be updated with a note about Rust 2021.

[lambda-fairy]

Thanks!

Yeah, I have the changes for this locally. Just need to clean it up.

I'll assign myself in the meantime.

[lambda-fairy]

BTW, the docs on main mention some unreleased features (#283). So to avoid confusion, I'll hold off on deploying the docs changes until I cut a new release.