Update changelog

Author: sosthene-nitrokey

CHANGELOG.md

@@ -4,9 +4,11 @@
 
 [Unreleased]: https://github.com/trussed-dev/serde-indexed/compare/0.1.1...HEAD
 
+- Add support for `#[serde(with)]` ([#16][])
 - Add support for `#[serde(skip)]` ([#14][])
 - Add support for generics ([#11][])
 
+[#16]: https://github.com/trussed-dev/serde-indexed/pull/16
 [#14]: https://github.com/trussed-dev/serde-indexed/pull/14
 [#11]: https://github.com/trussed-dev/serde-indexed/pull/11