Title: [Windows] Add a Keyboard Shortcut for Inserting a New Page

Please add a keyboard shortcut to insert a new page in Goodnotes for Windows.

Currently, users must manually click the "+" button to add a page, which interrupts the handwriting workflow.

I would like to suggest:

1. Ctrl + Enter to instantly insert a new page after the current page.
2. An option to customize this shortcut in Settings.
3. Support for the shortcut while using a stylus.

As a Windows PC user who frequently takes handwritten notes, this would greatly improve productivity and make note-taking more seamless.

Thank you!