Examine source code of Tagpacker

{
  "manifest_version": 2,
  "icons": {
    "24": "icon_24.png",
    "36": "icon_36.png",
    "128": "icon_128.png"
  },
  "name": "Tagpacker's \"Pack It\" Button",
  "short_name": "Pack It",
  "description": "Organize bookmarks your way. Faster than ever with the \"Pack it\" button.",
  "version": "1.0.16",
  "browser_action": {
    "default_icon": "icon_36.png",
    "default_title": "Pack it!"
  },
  "background": {
    "scripts": [
      "background-page.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "content-script.js"
      ],
      "css": [
        "content-script.css"
      ],
      "run_at": "document_start",
      "all_frames": false
    }
  ],
  "web_accessible_resources": [
    "outer-frame.html"
  ],
  "permissions": [
    "webRequest",
    "contextMenus",
    "activeTab",
    "notifications",
    "tabs",
    "*://*/*"
  ],
  "optional_permissions": [
    "bookmarks"
  ],
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "windows": "Ctrl+Shift+Y",
        "mac": "Command+Shift+Y",
        "chromeos": "Ctrl+Shift+Y",
        "linux": "Ctrl+Shift+Y",
        "default": "Ctrl+Shift+Y"
      }
    }
  },
  "omnibox": {
    "keyword": "tp"
  }
}