Component: star rating

[craigcook]

We should consider making a component for displaying an aggregate product rating from one to five stars, as well as allowing users to click and register their own rating. These likely need to be separate components: one for display-only and another for user rating.

For display, we could optionally show the total number of reviews alongside the stars, to indicate the basis for that aggregate score (for displaying aggregate scores we probably need to support half-stars but could force users to choose 1-5).

An expanded component might also include a breakdown chart showing how many people rated at each point.

Examples from addons.mozilla.org:

Examples from Amazon:

The most immediate use case for this component is addons.mozilla.org but it's a common enough pattern on the web we should considering making it widely available in Protocol.

[reemhamz]

This would be a good component to get Jessica's opinion on for the next Protocol meeting