Modal examples needed for testing

[jgiardino]

As noted in patternfly/patternfly#925, some working examples of the modal are needed to better understand how the aria and role attributes might affect the behavior of a modal in screen readers.

Can we have a WIP PR created with the following examples?

• example with aria-label (refer to core example "ModalBox No Header Example" and use of aria-label on .pf-c-modal-box)
• example with aria-labelledby
• example with aria-describedby
• example with contents included in the modal other than the aria-describedby contents, header, and buttons (refer to core example "ModalBox No Header Example" and use of <span id="modal-no-header-description">)
• one example where contents are text and one where contents are a form would be ideal

For each example above, there should be two examples:

• one with role="dialog" aria-modal="true"
• and one without these attributes

[rachael-phillips]

Closing this issue, completed