Examine source code of Tab Eject

{
  "manifest_version": 2,
  "name": "Tab Eject",
  "version": "0.0.1",
  "description": "A simple tool to pop the current tab out to a new window via user-customizable shortcut (defaults to Ctrl-Shift-w)",
  "homepage_url": "https://github.com/natasha-codes/firefox-tab-eject",
  "applications": {
    "gecko": {
      "id": "@firefox-tab-eject"
    }
  },
  "background": {
    "scripts": [
      "build/ejecter.js"
    ]
  },
  "commands": {
    "eject-current-tab": {
      "suggested_key": {
        "default": "Ctrl+Shift+E"
      },
      "description": "Send an 'eject-current-tab' event"
    }
  }
}