docs: align CODE_OF_CONDUCT.md wording with Contributor Covenant (#4630)

Co-authored-by: sanosuguru <sa.50.00.no.riku@gmail.com>

Author: sano-suguru

docs/CODE_OF_CONDUCT.md

@@ -14,8 +14,8 @@ diverse, inclusive, and healthy community.
 
 ## Our Standards
 
-Examples of behavior that contribute to a positive environment for our
-community includes:
+Examples of behavior that contributes to a positive environment for our
+community include:
 
 - Demonstrating empathy and kindness toward other people
 - Being respectful of differing opinions, viewpoints, and experiences