Add restriction on private contact of community members without permission (github#16570)

Co-authored-by: Janice <[email protected]>

Author: lee-dohm

CODE_OF_CONDUCT.md

@@ -22,6 +22,7 @@ Examples of unacceptable behavior include:
 * Trolling, insulting or derogatory comments, and personal or political attacks
 * Public or private harassment
 * Publishing others' private information, such as a physical or email address, without their explicit permission
+* Contacting individual members, contributors, or leaders privately, outside designated community mechanisms, without their explicit permission
 * Other conduct which could reasonably be considered inappropriate in a professional setting
 
 ## Enforcement Responsibilities