[Feature] Resource Viewer

[michael-hawker]

This may be part of "and more" for #6 ?

• Test more
• Document
• Add to Welcome Page as Feature

[michael-hawker]

While fixing #29 I realized the Resource Viewer doesn't play nice with the new tools like #11 and #12 (also didn't test #5).

• It'd be nice if when placing cursor in editor on an element that it scrolled that resource into view in the preview pane, kind of like the visual tree navigation works for the properties panel...