This extension shows how to use the commands manifest key to register keyboard shortcuts for your extension.
It registers a shortcut (Ctrl+Shift+U) to send a command to the extension (Command+Shift+U on a Mac). When the user enters the shortcut, the extension opens a new browser tab and loads https://developer.mozilla.org into it.
It also adds an options page to the extension, which enables the user to change the registered shortcut for the extension. Just open the options page, then type a new value into the textbox (for example: "Ctrl+Shift+O") and press "Update keyboard shortcut". To reset the shortcut to its original value, press "Reset keyboard shortcut".