Missing config attribute "promotion"

[fdendorfer]

According to the docs (https://www.tiny.cloud/docs/tinymce/latest/customize-ui/#premium-upgrade-promotion-option) promotion should be configurable, but currently isn't as a WebComponent. I think the fix should be to add the attribute to configAttributes in tinymce/tinymce-webcomponent/src/main/ts/component/Editor.ts. I might make a MR later unless that is intended to be non-configurable.

[fdendorfer]

Looks like a 'few' more as well, looking at tinymce/tinymce/modules/tinymce/src/core/main/ts/api/Options.ts