Docs feedback: MySQL to PostgreSQL

For the Source Installation section, I had the following issues which I think can greatly improve the migration process.

I had a mixture of PostgresSQL 10 (probably installed a few weeks back) and 11 installed (from the same docs, today) which was an issue trying to get the database tables created. Perhaps there should be steps to upgrade from older versions of PostgresSQL (from distro repo's) to the repo provided in the doc's. I essentially purged all Postgres packages, which is fine for new installations, but if there is existing data, a normal removal of the old version of Postgress should suffice, or is there more to it?
The repo version of PostgresSQL uses UNIX sockets by default. For step four, you might want to recommend commenting out password and host under production in config/database.yml so that connections via a UNIX socket succeeds. Alternatively, update the steps documented here https://docs.gitlab.com/ee/install/installation.html#6-database to set a password for the git user if connecting via a TCP connection.

Thanks