refs https://github.com/TryGhost/Admin/pull/2209
- `miragejs` has been extracted to a framework-independent library, the re-exports of `miragejs` elements in `ember-cli-mirage` have been deprecated making our test logs very noisy
- added `miragejs` as a top-level dependency
- updated all relevant imports to pull from `miragejs` instead of `ember-cli-mirage`
no issue
- fixed all `no-shadow` linter warnings
- changed `no-shadow` eslint rule from `warn` to `error` so we don't re-introduce shadowed variables in the future
no issue
- added `page` model
- removed `page` param from Post model
- added pages screen with associated links
- added `:type` param to editor screens to work with the right models
- removed post<->page toggle and associated tour item