Provide explanation for where user email came from (#1869)

* Provide explanation for where user email came from

* bringing back the newline

Author: yasonk

README.md

@@ -286,6 +286,7 @@ jobs:
           git commit -m "generated"
           git push
 ```
+*NOTE:* The user email is `{user.id}+{user.login}@users.noreply.github.com`. See users API: https://api.github.com/users/github-actions%5Bbot%5D
 
 # License