Mark book info from page and store it locally
This example adds a sidebar that lets you take notes on the current web page. The notes are saved to local storage, and the notes for each page are shown again when you open that page again.
The example also uses the commands manifest key to add a keyboard shortcut that opens the sidebar.
How to create a sidebar for an add-on. How to associate the sidebar with the currently active tab in that sidebar's window. How to store and restore sidebar content.