Multiplayer sync with custom people menu

A custom multiplayer people menu / facepile that displays connected collaborators.

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This example demonstrates how to build a custom people menu (or facepile) that shows information about all users in a multiplayer session.

This is useful when you want to create a more detailed or custom-styled presence indicator than the default tldraw provides. This example shows user's names, ids, colors, and cursor position, all information provided in the TLInstancePresence returned by editor.getCollaborators().