Text - support for hr element

[mcoker]

Core supports <hr> in the content/text component, it would be super duper to have support for it in the react text/textcontent component. Here is a use case in the docs framework package patternfly/patternfly-org#4011 (comment)

https://github.com/patternfly/patternfly/blob/ce84441970fd1a48ad391659a4452bff0ae47139/src/patternfly/components/Content/content.scss#L300-L307

cc @wise-king-sullyman