Fix broken anchor links in readme (#893)

Co-authored-by: Éric <635179+merwok@users.noreply.github.com>

Author: ofek

README.md

@@ -38,11 +38,11 @@ support for [JSON](https://json.org), [MessagePack](https://msgpack.org),
   [attrs](https://www.attrs.org),
   [structs](https://jcristharif.com/msgspec/structs.html) should feel familiar.
   However, they're
-  [5-60x faster](https://jcristharif.com/msgspec/benchmarks.html#benchmark-structs>)
+  [5-60x faster](https://jcristharif.com/msgspec/benchmarks.html#structs)
   for common operations.
 
 All of this is included in a
-[lightweight library](https://jcristharif.com/msgspec/benchmarks.html#benchmark-library-size)
+[lightweight library](https://jcristharif.com/msgspec/benchmarks.html#library-size)
 with no required dependencies.
 
 ---