Add migration path for people moving off of Select Preview to Compound Select in Main

[mannycarrera4]

💡 Suggestion

Since we're removing Select in Preview and a codemod isn't exactly easy, we should provide a migration path/ discussion on how to do this.

[mannycarrera4]

I'm going to close this. There's been multiple stackblitz shared to show the difference and most people are using the one in Main.