feat: Adds new legacy maps sample for div element.

[willum070]

This PR duplicates the map-simple sample for retention as a way to demonstrate the legacy pattern.

[snippet-bot]

Here is the summary of changes.

You are about to add 3 region tags.

• samples/map-simple-legacy/index.html:7, tag maps_map_simple
• samples/map-simple-legacy/index.ts:7, tag maps_map_simple
• samples/map-simple-legacy/style.css:6, tag maps_map_simple

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