Must interact modal

[swierczek]

Overview

Adding an example of new modal functionality to require interaction in order to close a modal.

Nature of This Change

• [ ] 🐛 Fixes a bug
• [x] 🚀 Implements a new feature
• [ ] 🛁 Rewrites existing documentation
• [ ] 💅 Fixes coding style
• [ ] 🔥 Removes unused files / code

Related Application Change

Application Pull Request: https://github.com/ExpressionEngine/ExpressionEngine/pull/4719