aria-disabled should be focusable

[kee-oth]

Currently, focus-trap doesn't allow for focusing of elements with aria-disabled=true. For accessibility reasons, aria-disabled=true is often used instead of disabled to allow for the element to be tabbed to. Can we at least get an opt-in option to not consider elements with aria-disabled=true when determining whether it can be focused?

Thanks!

https://github.com/andreasbm/focus-trap/blob/efe549115288362d2aaae9b7a4780cc4539d097d/src/lib/focusable.ts#L29