A lot of the time users are using the document, it's in order to dynamically generate a page. However, when dynamically generating a page, most of the time you're working with String's, not just &str's. Currently, many Document methods only take an &str, which means that each time you call a method with something like the output from `format!()`, you need to add a `.as_str()`, which adds just a little bit of clutter.
This change makes it so that Document methods that previously took an `&str` can now take an `impl AsRef<str>`, which allows users to pass either an `&str` or a `String`.
Emi Tatsuo
panicbit