refs https://github.com/TryGhost/Team/issues/771
- updated `<GhImageUploaderWithPreview>` to take an `@includeMetadata` argument that shows a basic html supporting caption field underneath (ready for toggle between caption/alt but not fully implemented)
- added feature image alt/caption properties to post model
- updated UI behind "featureImageMeta" labs flag
- added the feature image uploader to the top of `<GhKoenigEditor>` for display above the editor title
- removed feature image uploader from post settings menu
- added labs flag checkbox
no issue
Keeps component JS backing files and template files in the same directory which avoids hunting across directories when working with components. Also lets you see all components when looking at one directory, whereas previously template-only or js-only components may not have been obvious without looking at both directories.
- ran [codemod](https://github.com/ember-codemods/ember-component-template-colocation-migrator/) for app-level components
- manually moved in-repo-addon component templates in `lib/koenig-editor`
- removed all explicit `layout` imports as JS/template associations are now made at build-time removing the need for them
- updated `.embercli` to default to new flat component structure
