Converted Rotate.js operations to ESM modules

[mattnotmitt]

Content

Converted four operations:

• ROT13
• ROT47
• Rotate left
• Rotate right

Additionally created lib/Rotate.mjs, which contains shared default options & shared functions.

TODO

• Write tests

[n1474335]

Thanks very much for this, especially the new tests. I'll start working on a migration script soon, but I suspect it'll be more of a helper than a full solution. We're still going to have to go through every operation manually as there is a lot to change. It's a good opportunity to review and refactor everything though - never a bad idea!

My next focus is on the present() method and a good Node API. Once we have those nailed down we'll be looking to convert the rest of the operations, so anything you can help with will be greatly appreciated.