you need this kind of explanation

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/10/static/index.html
Description:

right off the bat, you should have this kind of explanation up there in
chapter 1:

https://www.liquidweb.com/kb/what-is-the-default-password-for-postgresql/

this will orient any noobs immediately.

also, the word "role" and "user" should not be used interchangebly. they
mean different things.