Docs: convert API Table to use <sp-table>

[najikahalsema]

On the docs site, the current API table is built with Spectrum CSS. We should update this to use the <sp-table> component, since we have it now.

[Westbrook]

An old draft of this is available here for reference. It currently supports a very fixed layout, which is very different than what the <table> approach gave up.

<table>

<sp-table>

Notice the forced overflow scrolling, even when the content could "collapse" while still looking correct.

This may be a hard requirement for <sp-table> while subgrid is not available x-browser, but it would be good to have a solid perspective on delivering <sp-table> in responsive contexts for our consumers.

[Westbrook]

This went in some while back and didn't get closed at merge time. Shipped!