New comment by Chocimier on void-packages repository

https://github.com/void-linux/void-packages/pull/18103#issuecomment-572164213

Comment:
Upgrading with `pg_upgrade` requires to have binaries of both version installed at the same time, and updating with `pg_dumpall` require to bump database before uninstalling old version. Simply upgrading package will make exisiting databases unusable. I am working on separate packages installing version 12 aside, will push in-progress state soon.