Replace serde_urlencoded link with serde_qs

Author: dtolnay

_src/README.md

@@ -58,7 +58,7 @@ Serde by the community.
   definition.
 - [JSON5], A superset of JSON including some productions from ES5.
 - [Postcard], a no\_std and embedded-systems friendly compact binary format.
-- [URL], the x-www-form-urlencoded format.
+- [URL] query strings, in the x-www-form-urlencoded format.
 - [Envy], a way to deserialize environment variables into Rust structs.
   *(deserialization only)*
 - [Envy Store], a way to deserialize [AWS Parameter Store] parameters into Rust
@@ -80,7 +80,7 @@ Serde by the community.
 [BSON]: https://github.com/zonyitoo/bson-rs
 [Avro]: https://github.com/flavray/avro-rs
 [JSON5]: https://github.com/callum-oakley/json5-rs
-[URL]: https://github.com/nox/serde_urlencoded
+[URL]: https://docs.rs/serde_qs
 [Postcard]: https://github.com/jamesmunns/postcard
 [Envy]: https://github.com/softprops/envy
 [Envy Store]: https://github.com/softprops/envy-store