Use recently stabilized intra-doc links

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

native/src/clipboard.rs

@@ -2,7 +2,5 @@
 /// applications.
 pub trait Clipboard {
     /// Returns the current content of the [`Clipboard`] as text.
-    ///
-    /// [`Clipboard`]: trait.Clipboard.html
     fn content(&self) -> Option<String>;
 }