[Feature Request] default validator message boilerplate

[guoyunhe]

Laravel provides a command php artisan lang:publish which will eject all framework built-in validator/error handling messages to lang/en/messages.php.

This is a very convenient way to start translation. Otherwise, you have try and guess which message key need to be translated.

My suggestion: when run node ace add @adonisjs/i18n, auto create /resources/lang/en/validator.json. So that users can use it to start translation.

[lfjsa]

I have the same problem, where I don't know which messages possibly exist. Digging through the source code proved unsuccessful.

[thetutlage]

@guoyunhe Does make sense. Would you be interested in creating a PR for it?