Add a simple tutorial for using the Quick Editor from a SwiftUI View

[andrewdmontgomery]

Closes #508

Description

Adds a DoCC tutorial for using the Quick Editor

Testing Steps

[andrewdmontgomery]

So far this just shows using the .verticleLarge layout. I will add two more layouts to this section.

Then I thought I would add a section for using the avatarUpdateHandler, at least.

[wpmobilebot]

📲 You can test the changes from this Pull Request in Gravatar SwiftUI Prototype Build by scanning the QR code below to install the corresponding build.

	App Name	Gravatar SwiftUI Prototype Build
	Build Number	1616
	Version	1.0
	Bundle ID	com.automattic.gravatar-sdk-demo-swiftui.prototype-build
	Commit	700a1d7faf12143ac948db58a912f6c02d139c2e
	App Center Build	Gravatar SDK Demo - SwiftUI #322

Automatticians: You can use our internal self-serve MC tool to give yourself access to App Center if needed.

[wpmobilebot]

📲 You can test the changes from this Pull Request in Gravatar UIKit Prototype Build by scanning the QR code below to install the corresponding build.

	App Name	Gravatar UIKit Prototype Build
	Build Number	1616
	Version	1.0
	Bundle ID	com.automattic.gravatar-sdk-demo-uikit.prototype-build
	Commit	700a1d7faf12143ac948db58a912f6c02d139c2e
	App Center Build	Gravatar SDK Demo - UIKit #323

Automatticians: You can use our internal self-serve MC tool to give yourself access to App Center if needed.

[pinarol]

Looks good, let's add a link to this tutorial here as well: