rewrite accessibility section on invokers

[keithamus]

This rewrites the a11y section on invokers to be far more comprehensive, detailing the exact intentions we have when it comes to applying various ARIA states to the button, as well as focus fixups.

[mfreed7]

Wow, awesome new section! This looks good to me, but I'm not the right person to judge it. I'll stamp this approved, because I'm ok landing it and putting up PRs to improve it over time. But @scottaohara and @aleventhal please take a look and also @ mention anyone else that should have a look.

[scottaohara]

i'll review this later today or tomorrow. thanks @keithamus

[scottaohara]

let me know if there are questions with my comments

[mfreed7]

let me know if there are questions with my comments

@keithamus is the plan still to update this with @scottaohara 's comments before landing? (I hope so.)

[scottaohara]

we are going to need the HTML AAM PR for this as well, so whether fixed here or in that PR (and then this gets updated to just say 'go look at html aam' instead) is fine by me.

but from what i understand, we are going to need that HTML AAM PR to land at the same / close to the same time as the HTML PR. so we need to get that going / address the above either way.

[keithamus]

@scottaohara I believe I've addressed your review commentary. If you would kindly give it another pass that would be much appreciated.

[scottaohara]

approving with minor additional suggestions. take them as you will. thank you!

[keithamus]

Thanks @scottaohara! I'll merge and get to work on the AAM PRs!

[scottaohara]

Thanks @scottaohara! I'll merge and get to work on the AAM PRs!

excellent. thank you. just give me a holler if you have any questions when making that PR.