Fix header link for The Rust Representation

Author: ehuss

src/type-layout.md

@@ -207,7 +207,8 @@ not change the layout of the fields themselves. For example, a struct with a
 `C` representation that contains a struct `Inner` with the default
 representation will not change the layout of `Inner`.
 
-### <a id="the-default-representation"></a> The `Rust` Representation
+<a id="the-default-representation"></a>
+### The `Rust` Representation
 
 r[layout.repr.rust]