CODE-OF-CONDUCT.md

Code of conduct

This project operates under the Rust code of conduct which can be found at https://www.rust-lang.org/policies/code-of-conduct

The current recognised version of that is found at: https://github.com/rust-lang/www.rust-lang.org/blob/33788e824fa0b5390212dc7a3983233c0a8f60be/locales/en-US/code-of-conduct.ftl