Add Example App

[thecoolwinter]

Description

• Adds an example app. Just a barebones example of how to use the TextView class to create a plain-text editor.
• The project is set up so the package is a local, editable, dependency.

This has been extremely useful in CESE, and should help when developing this package. It's also good documentation, and we can point people towards this example app if they'd like to see how to use the text view.

Related Issues

• N/A

Checklist

• I read and understood the contributing guide as well as the code of conduct
• The issues this PR addresses are related to each other
• My changes generate no new warnings
• My code builds and runs on my machine
• My changes are all related to the related issue above
• I documented my code

Screenshots

[austincondiff]

Great idea!