Official pfe-content-set status

- [x] schema
- ~~theme support~~
- [x] framework support
    - [x] Angular
      - Need to merge https://github.com/patternfly/patternfly-elements/pull/406
    - [x] React
    - [x] Vue
- [x] no major outstanding bugs
    - [[ object object ]] ?
        - fixed here: https://github.com/patternfly/patternfly-elements/pull/406/commits/86ce1a66dfbd648b7408d0051a9cb1f404695c4a