Header bar font is different on front page and rustdoc files

[jyn514]

Regression introduced in #930.

@Nemo157 suggested this is because the writer puts the navigation nested under .rustdoc and the style sets the .rustdoc font differently. We probably just need an override resetting the nav-bar font style to what's used for the rest of the body outside rustdoc.

[cynecx]

Moving the "topbar" out of the tranformed rustdoc body should fix this (Hence using the correct font-family and not the overwritten one by the css class div.rustdoc). Tbh it doesn't make much sense to have the topbar in the rustdoc container since it has position: fixed anyway.

If this is the desired approach, I could open a PR.

[jyn514]

That sounds good to me! I think the way to implement this is by moving it from templates/rustdoc/body.html to templates/rustdoc/head.html.

[cynecx]

@jyn514 Mh. I don't think that's a good idea? That would put the nav-container div inside the head element which is not a good idea (as I understand it is invalid HTML5). Afaict changes to https://github.com/rust-lang/docs.rs/blob/master/src/utils/html.rs are required, no? (In order to put the topbar before the actual rustdoc container.)