Move the document trait into a separate crate (#3035)

* add a default head method through eval
* remove the old document trait
* implement document for each platform
* pull out document into a dedicated crate to cut down on shared dependencies
---------

Co-authored-by: Jonathan Kelley <jkelleyrtp@gmail.com>

packages/html/src/lib.rs

@@ -41,9 +41,6 @@ pub use elements::*;
 pub use events::*;
 pub use render_template::*;
 
-#[cfg(feature = "document")]
-pub mod document;
-
 pub mod extensions {
     pub use crate::attribute_groups::{GlobalAttributesExtension, SvgAttributesExtension};
     pub use crate::elements::extensions::*;
@@ -51,11 +48,6 @@ pub mod extensions {
 
 pub mod prelude {
     pub use crate::attribute_groups::{GlobalAttributesExtension, SvgAttributesExtension};
-    #[cfg(feature = "document")]
-    pub use crate::document::{
-        self, document, eval, head, Document, Meta, MetaProps, Script, ScriptProps, Style,
-        StyleProps, Title, TitleProps, UseEval,
-    };
     pub use crate::elements::extensions::*;
     pub use crate::events::*;
     pub use crate::point_interaction::*;