docs: example output

[dckc]

this visualization It has a slider to "animate" crank by crank. At a given crank, for each vat, it shows the vatID and annotated name plus export clist. It shows outstanding sends (dashed) along with the current message or notify (solid).
And it shows a dotted line for imports that haven't been dropped.

This was the original goal: to show what vats have what capabilities at the end of bootstrap. It's still too noisy, but the resulting layout gives a rough sense of reliance.

Here's what it shows at crankNum 471 of 1504

[dckc]

an example we went over in a couple meetings today: