It would be nice to be able to click a little "pin" button on the preview window and have the preview stop refreshing. This way a user could navigate to some documentation, click "pin," then go somewhere else in the code and use the documentation as reference while they work.

Added a "pause" button to the toolbar so you can pause/unpause the preview window. Pausing makes it so the preview never refreshes and allows you to navigate all over without it changing. Unpausing instantly refreshes the preview and resumes the default behavior of [relatively] real-time updating.