Fixes #88. Make element hiding opt-in by removing an optional 'unresolved' attribute from the web component element that allows users to style based on the existence, or lackthereof.
Update documentation.
Better test explanations.
Resolves #90. Add 'resolved' attribute after 'unresolved' is removed.
Add documentation note about the 'resolved' attribute.
Update options example to included resolved / unresolved attributes.
Merge pull request #89 from skatejs/GH-88

Fixes #88. Make element hiding opt-in by removing an optional 'unresolve...