Examine source code of Single Key Browsing

{
  "name": "Single Key Browsing",
  "version": "1.3.0",
  "manifest_version": 2,
  "description": "A few single key shortcuts for common browsing actions",
  "icons": {
    "48": "icons/48.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "storage",
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "icons/32.png",
    "default_title": "Enable/disable key shortcuts"
  },
  "content_scripts": [
    {
      "js": [
        "page.js"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{039eb3aa-a70a-4f38-a179-43d601ce7c56}"
    }
  }
}