Included since 0.2.19

Issue	Description
431	Add support for multiple workspaces. WORK IN PROGRESS
443	Switch workspace via shortcuts
457	Support snippets of test configuration to be merged into settings

PR	Author	Description

Other changes
New poly-rcf example workspace that shows how to run Hyperfiddle rcf tests with the `poly` tool.
If `:hide-lib-size` is given to the `libs` command, values in the `KB` column appear as `-`. Used for testing purposes.

Doc updates
New sponsor: taehee-sp (김태희)
Remove Funnel as example production system.

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