Can't collapse accordion sections with [ui-accordion open=none]

When using `[ui-accordion open=none]`, I'm unable to re-collapse accordion sections after opening them. I can only open **other** sections, (which thus collapses the original section). I have some lengthy sections, so it would be very nice if users could collapse opened sections instead of scrolling to see/open next section.

Also - Feature request for ability to link to tabs/accordions?

Start by reproducing the behavior with the [ui-accordion open=none] shortcode and inspect the accordion implementation. Confirm that an opened section can be collapsed again without opening another section; the separate request to link to tabs or accordions is broader and needs its scope clarified.

Written by the indexing model from the issue text.