docs: fix RAC ExampleSwitcher rendering in markdown docs

[reidbarber]

Fixes markdown docs rendering of the RAC ExampleSwitcher examples (Vanilla/Tailwind).

✅ Pull Request Checklist:

• Included link to corresponding React Spectrum GitHub Issue.
• Added/updated unit tests and storybook for this change (for new code or code which already has tests).
• Filled out test instructions.
• Updated documentation (if it already exists for this component).
• Looked at the Accessibility Practices for this feature - Aria Practices

📝 Test Instructions:

Open the markdown page for some RAC docs and verify that the Vanilla/Tailwind examples and file contents get rendered.

Example: https://d5iwopk28bdhl.cloudfront.net/pr/76038188b8ed88d9a1e6ba490247c09cddfded59/Autocomplete.md

🧢 Your Project:

[rspbot]

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• View the storybook
• View the S2 storybook
• View the S2 docs
• View the React Aria docs