docs(design-guidelines): Consider alternative solution for components without design guidelines.

[edonehoo]

Right now, there are some components with no design guidelines, simply due to the fact that there really aren't any to offer. For example: https://www.patternfly.org/components/backdrop/design-guidelines. We received feedback via the org survey that it's confusing when there's just a link to the a11y docs under an Accessibility heading.

Do we need to have a design guidelines tab in these cases? Could we add an H1 to clarify this more? Or an alert? Or is it fine as is?

Explore a few ideas and take note of the components this applies to