Migrate tool for October CMS users

[bennothommo]

Mercator from Discord suggested a great feature - a migrate command to automatically switch an October website over to Winter.

We could possibly do the following:

• Run a check to make sure a compatible version exists
• Switch out the Composer dependencies
• Adjust the bootstrap/autoload.php file
• ....
• Profit? (not monetarily, but from goodwill for converting another happy user to Winter CMS)