Add chat-widget example demonstrating @lume/element and Meteor integration#2

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copilot/fix-e9a6a591-7282-4aa8-b4f8-1c76918e75falume/lume.github.io:copilot/fix-e9a6a591-7282-4aa8-b4f8-1c76918e75faCopy head branch name to clipboard