add trailing newline

Author: He1pa

compiler/rustc_error_codes/src/error_codes/E0793.md

@@ -89,4 +89,4 @@ See [issue #82523] for more information.
 
 [packed]: https://doc.rust-lang.org/reference/type-layout.html#the-alignment-modifiers
 [undefined behavior]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html
-[issue #82523]: https://github.com/rust-lang/rust/issues/82523
+[issue #82523]: https://github.com/rust-lang/rust/issues/82523