Menu toggle - update status examples, add demo

[mcoker]

Add text blurb to status menu toggle example saying you need to use helper text w/ warning and danger. We can use the wording in the react example - https://www.patternfly.org/components/menus/menu-toggle/#status-toggle

When the status value is "warning" or "danger", you must include helper text that conveys what is causing the warning/error.

Also add menu toggle demo with status menu toggle(s) in a form with helper text. There is also a react issue to add this same demo, and core/react should match if possible