Incorporate AMP validator into post authorship flow, to alert if content within the post editor is not compatible with AMP #843
Description
Acceptance Criteria
AC1: On saving a post on /wp-admin/post.php, if there’s post content that’s not compatible with AMP, display an error at the top of the page.
AC2: The error will not display specifically what is incompatible.
AC3: The error will display the following text: “Notice: your post fails AMP validation”.