docs(readme): Add a hyphen

Author: epage

README.md

@@ -19,7 +19,7 @@ at your option.
 
 Unless you explicitly state otherwise, any contribution intentionally
 submitted for inclusion in the work by you, as defined in the Apache-2.0
-license, shall be dual licensed as above, without any additional terms or
+license, shall be dual-licensed as above, without any additional terms or
 conditions.
 
 [Crates.io]: https://crates.io/crates/PROJECT