New comment by Chocimier on void-packages repository

https://github.com/void-linux/void-packages/issues/243#issuecomment-541504793

Comment:
I tried once with goal to allow use pg_upgrade but I was not glad with [results](https://github.com/Chocimier/void-packages-org/tree/postgres11). This version is not even tested, I guess.

However, I take some [notes](https://github.com/Chocimier/void-packages-org/blob/postgres11/srcpkgs/postgresql/notes) that may be more useful.