Smaller format for license section

README.md

@@ -81,19 +81,19 @@ good response, we are happy to respond to [GitHub issues][issues] as well.
 [irc]: https://wiki.mozilla.org/IRC
 [issues]: https://github.com/serde-rs/serde/issues/new/choose
 
-## License
+<br>
 
-Serde is licensed under either of
+#### License
 
- * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
-   http://www.apache.org/licenses/LICENSE-2.0)
- * MIT license ([LICENSE-MIT](LICENSE-MIT) or
-   http://opensource.org/licenses/MIT)
+<sup>
+Licensed under either of <a href="LICENSE-APACHE">Apache License, Version
+2.0</a> or <a href="LICENSE-MIT">MIT license</a> at your option.
+</sup>
 
-at your option.
-
-### Contribution
+<br>
 
+<sub>
 Unless you explicitly state otherwise, any contribution intentionally submitted
 for inclusion in Serde by you, as defined in the Apache-2.0 license, shall be
 dual licensed as above, without any additional terms or conditions.
+</sub>