Meter Example: Document and test pause button and aria-hidden

[mcking65]

We added a pause button to the meter example. It is not documented under keyboard interaction. It is not tested. Perhaps we should also add an accessibility features section that describes the rationale for including it.

The aria-hidden attribute on the SVG is not documented. Should it be?

[ZoeBijl]

The pause button doesn’t need to be included in the keyboard interaction I don’t think. It’s not part of the pattern, only the example itself. The alert code example has a button to trigger the alert. But it doesn’t have that detailed in the keyboard interaction. It does have an accessibility features section and I’m in favour of adding that here too.

Undecided about the aria-hidden. It’s also not part of the pattern but rather the code example. Perhaps that could be included in the accessibility features section too?

[a11ydoer]

Here is the completed meter example. To my understanding, documentation and coding example works are done. I think I was supposed to do regression tesing... @spectranaut can confirm whether we need the regression testing for this example or not?