Convert to v2 add-on format

[SergeAstapov]

Looks like this add-on is great candidate for v2 add-on format aka Embroider native conversion.

@kategengler I see you started working on v11 - do you think we could e.g. add ember-auto-import@2 as a dependency as part of v11 release so we don't need another major version bump for the actual conversion to v2 format?

[kategengler]

@SergeAstapov I don't think we will run out of numbers. There are some major changes queued up -- I'm not actually trying to release a v11 but a v10.1.1. Working on the release infrastructure with the v11 beta.

[SergeAstapov]

There are some major changes queued up

noted, looking forward to see those.

Will close for now

[kategengler]

Sorry maybe I wasn't clear -- those changes are already on master, so the PR should be fine. There's also #852 which does convert to v2, I think.