Add Ruby support

[doron050]

The ruby ecosystem is very much alive, you can see it in Ruby 2023 ecosystem report by Jetbrains, and as a developer and an SQLC user, I think the project can benefit by supporting as many language runtimes as possible + if there is Python, why not Ruby? :)

@SockworkOrange and I are close to releasing the 1st (though mature) version of our C# plugin, and we want to start working on a ruby one.

[SockworkOrange]

Considering this comment on the corresponding C# issue -
"if someone would like to try their hand at C# support, you aren't blocked getting your changes into the sqlc codebase"

@doron050 and I have also started working on adding Ruby support (implemented in Ruby) in here - https://github.com/DaredevilOSS/sqlc-gen-ruby