small grammar fix (#2979)

let me know if you think it reads better. thanks!

CODE_OF_CONDUCT.md

@@ -6,7 +6,7 @@ contribute through reporting issues, posting feature requests, updating
 documentation, submitting pull requests or patches, and other activities.
 
 We are committed to making participation in this project a harassment-free
-experience for everyone, regardless of level of experience, gender, gender
+experience for everyone, regardless of the level of experience, gender, gender
 identity and expression, sexual orientation, disability, personal appearance,
 body size, race, ethnicity, age, religion, or nationality.