Accordion - add advanced options

[trubach]

There are a few advanced options the toolbox accordion can handle that aren't built into the accordion paragraph. The options that need to be added are:

• [ ] Allow only one accordion row expanded at a time (i.e. close all other accordions when clicking on a row)
• [ ] Allow bordered accordion rows vs. the solid option that is the current default
• [ ] Option on each row to default the details to be expanded by default

Each one of these options will require a new field added to the paragraph.

Ideally, these options won't be visible initially. We could add an "Advanced settings" link/button to the paragraph edit form that when clicked on, brings up the extra settings.

Implementation details can be found at the toolbox at https://github.com/web-illinois/toolkit/wiki/il-accordion

[mwllr]

What about accordions within an accordion??? I'll need to do this page soon: https://hdfs.illinois.edu/undergraduate/faq @trubach