Live demo in ChangesetForm documentation page is broken

[MichalBryxi]

• See: https://frontile.dev/docs/changeset-form/usage/
• Page seems to render ok, but the live demo does not render

The error reads:

Error: Could not find module `@ember/string` imported from `ember-changeset-validations/utils/messages`

[MichalBryxi]

Wanted to help with this, but until #324 is resolved I don't think I will be of any use :-/

[josemarluedke]

I have see this error in some projects, the solution is to downgrade @ember/string to v3, v4 causes this error.