Expand and revise examples section
Added the examples already sketched out in the document and added some more based on a tentative approach to MVP functionality.
/agenda
@DRx3D I've updated the attribute for providing orbit input from interactive to stagemode="orbit".
(there is also an established HTML attribute called inputmode but it seems to relate specifically to textual input, so it may be better to pick a different name)
@DRx3D After some investigation and discussion, it seems that a top-level src attribute overrides anything coming from a set of <source> elements within <video>. I think we should follow their lead and have updated to reflect that.