Type Aliases section title not rendered correctly

[johnthagen]

The ticks around "type" are not rendered correctly in the rust book.

https://doc.rust-lang.org/book/type-aliases.html

[johnthagen]

Also here: https://doc.rust-lang.org/book/const-and-static.html