[README.md] Add offscale/postgres-version-manager-go

[SamuelMarks]

Your project is great!

I've used it in mine, which was originally based on the other Go project but has since deviated significantly.

postgres-version-manager-go

Like rvm/nvm but for PostgreSQL. Installs any of 140+ different versions of PostgreSQL for your system.

https://github.com/offscale/postgres-version-manager-go

Unlike the other solutions, mine is purposed primarily to be called from the command-line.

It [opt-out] stores configuration into a file and can even install system daemons.

PS: How do you want me to reference your project in my README?

[tomix26]

A mention at the bottom of the readme is enough.