docs(refresher): add component playgrounds

[brandyscarney]

Adds the following component playgrounds:

• Basic Usage (a simple usage example with text content and a pull to refresh)
• Advanced Usage (a more advanced usage example with a list and items appended to the beginning on refresh)
• Pull Properties (a simple usage example with text content and a pull to refresh with custom pull properties)
• Custom Refresher Content (a simple usage example with text content and a pull to refresh with a custom refresher content)
• Usage with Virtual Scroll (a simple usage example with text content and a pull to refresh with a custom scroll target)

Preview Link: https://ionic-docs-git-fw-1273-ionic1.vercel.app/docs/api/refresher

[vercel]

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Name	Status	Preview	Updated
ionic-docs	✅ Ready (Inspect)	Visit Preview	Oct 25, 2022 at 3:28PM (UTC)

[brandyscarney]

I removed the unused imports, added a description for advanced usage and moved it to the bottom. Let me know if you see any issues!

[sean-perkins]

Looks good to me 👍

[averyjohnston]

I think you really nailed it with the code balance 👍 Just had a couple content-related comments.