doc: update list of personal traits in CoC

https://github.com/rust-lang/rust-www/pull/288 landed in the Rust repo
so it seems like a good idea to just bring the updated list in.

We also received a request to do this in https://github.com/nodejs/inclusivity/issues/82
so this should resolve that.

Thanks to [@Charlotteis](https://github.com/Charlotteis) for bringing
up the original issue.

Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: Myles Borins <mborins@us.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>
PR-URL: https://github.com/nodejs/node/pull/4801
Fixes: https://github.com/nodejs/inclusivity/issues/82

CODE_OF_CONDUCT.md

@@ -1,11 +1,14 @@
 ## Code of Conduct
 
 This Code of Conduct is adapted from [Rust's wonderful
-CoC](http://www.rust-lang.org/conduct.html).
+CoC](http://www.rust-lang.org/conduct.html) as well as the
+[Contributor Covenant v1.3.0](http://contributor-covenant.org/version/1/3/0/).
 
 * We are committed to providing a friendly, safe and welcoming
-  environment for all, regardless of gender, sexual orientation,
+  environment for all, regardless of level of experience, gender
-  disability, ethnicity, religion, or similar personal characteristic.
+  identity and expression, sexual orientation, disability,
+  personal appearance, body size, race, ethnicity, age, religion,
+  nationality, or other similar characteristic.
 * Please avoid using overtly sexual nicknames or other nicknames that
   might detract from a friendly, safe and welcoming environment for
   all.