Adds accordion demo link

[tesk9]

Component Catalog change only.

[krinhorn]

I think this would be more parsable as a list if that wouldn't cause issues or if you aren't super against it. Ex:

• The Accordion component is designed to be used when you have either a list or a tree of expandables. It may also be used when there's only one expandable.
• Devs should watch the entirety of Tessa's Accordion demo before using. Discussion of how to attach styles correctly begins at 5:10.

[tesk9]

[charbelrami]

Looks good!