Provide a way to switch between components quickly

[notlee]

It's come up a couple of times that users would like a quick way to switch from
one component to another in the registry, from a component's demo page, e.g:
https://financialtimes.slack.com/archives/CSW6B2VAN/p1615985835010900
https://financialtimes.slack.com/archives/C02FU5ARJ/p1583428808042900

A previous iteration of the registry (going back a year or two?) always listed
components in a left-hand side bar which was ideal for switching components
quickly. However that space is now contextual to support navigating demos,
the readme, codedocs, etc, which didn't used to exist in the registry.

Is there a way we can/should reintroduce quick component switching? Maybe
with full origami.ft.com search in the header? And or a search component shortcut?

[chee]

maybe we should have a Sublime Text/Slack-like Jump To menu for power users

[chee]

we really need design to look at this at some point. it is confusing UX to have a global searchbox that becomes a filter on other pages. i understand the logic behind it, but it's confusing to use.