[Docs]: Include Positioning Docs Link For `positioning` props

[SpencerLynn]

Area

React Components (https://react.fluentui.dev)

What kind of documentation issue are you reporting?

• [ ] Reporting a typo
• [ ] Reporting a documentation bug
• [x] Documentation improvement
• [ ] Documentation feedback

Is there a specific documentation page you are reporting?

https://react.fluentui.dev/?path=/docs/components-avatargroup--docs

There are possibly others.

Description

The AvatarGroupPopover component has a postioning prop. The type for this prop is quite complex and supports lots of options (which is great). However, it can be a lot to navigate when looking for functionality.

It might be nice to link the positioning docs for this prop - and for any other components that leverage this prop.

For context, I recently was needing to offset the popover on the AvatarGroupPopover and wound up doing some non-ideal workarounds before realizing the positioning prop offers an offset option. It wasn't obvious in the component docs, and I got lost in the types and ended up giving up on the positioning prop prematurely :(

Validations

• [x] Check that there isn't already an issue that requests the same feature to avoid creating a duplicate.