Generator custom exit message

[Akryum]

What problem does this feature solve?

Displaying some instructions after invoking a 3rd-party plugin improves the Dev Exp.

For example: Start the server with this command.

It may be useful for erros too?

What does the proposed API look like?

// generator.js
api.exitMessage = `Start server with '...'`

The message would be displayed here:

vue-cli/packages/@vue/cli/lib/invoke.js

Line 127 in 46166fb

log()