Examine source code of Widicionário

{
  "manifest_version": 2,
  "name": "Widicionário",
  "version": "0.0.1",
  "author": "MCA",
  "description": "Facilita a sua buscar por significados em páginas da web.",
  "icons": {
    "48": "icons/wd-48.png",
    "96": "icons/wd-96.png"
  },
  "background": {
    "scripts": [
      "menu.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ]
    }
  ],
  "permissions": [
    "http://*/*",
    "https://*/*",
    "contextMenus",
    "storage",
    "cookies",
    "webRequest",
    "webRequestBlocking",
    "tabs",
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{d680ee98-c7e8-4b3c-a7aa-cbb09c4b3aac}"
    }
  }
}