Close open accordion tab with escape key, when tabbing away

[nlhkabu]

Currently, it is possible to open and close the accordion component (seen on the search results page) using the keyboard.

However, it would be nice to:

• Automatically close the open accordion section (accordion__content) when the user tabs to the next accordion trigger (accordion__link)
• Allow the user to close the current section (accordion__content) using the esc key

[nlhkabu]

I have moved this out of the OTF milestone - I think this is a "nice to have" rather than a blocking issue. We can move it back into the milestone if we have the time/budget.