Overflow menu: Usage tab

[thyhmdo]

Ref Discussion https://github.com/carbon-design-system/carbon-website/discussions/3132

Usage tab

• Question: As per the discussion of "Is overflow menu a button variant?":
  The Overflow menu component will be leveraging menu under the hood, as will things like context menu, combo button, and menu button. Overflow menu will be housed with menuinstead of button. This question has been resolved.

• Usage template: Update content using the usage template.

• Formatting section: This image should have a focus indicator on the first option in the menu. Maybe do a split image here of an overflow without the danger hover, showing the rule divider mentioned in the content above. Then show the overflow menu danger hover beneath.

[laurenmrice]

Blocked until we figure out the content structure of Menu in our website docs.

[laurenmrice]

Unblocked. We can move forward with placing the Overflow menu Usage/Style documentation within the new Menu buttons page on the website.

[laurenmrice]

This was resolved with #3700