Use recently stabilized intra-doc links

See RFC: https://github.com/rust-lang/rfcs/blob/master/text/1946-intra-rustdoc-links.md

wgpu/src/backend.rs

@@ -30,8 +30,6 @@ pub struct Backend {
 
 impl Backend {
     /// Creates a new [`Backend`].
-    ///
-    /// [`Backend`]: struct.Backend.html
     pub fn new(device: &wgpu::Device, settings: Settings) -> Self {
         let text_pipeline =
             text::Pipeline::new(device, settings.format, settings.default_font);