Examine source code of Show Week Number

{
  "manifest_version": 2,
  "name": "__MSG_ic3Name__",
  "description": "__MSG_ic3Desc__",
  "version": "1.2",
  "author": "Ömer İpek",
  "default_locale": "en",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "16": "icons/week-16.png",
    "32": "icons/week-32.png",
    "48": "icons/week-48.png"
  },
  "browser_action": {
    "default_icon": "icons/week-48.png",
    "default_title": "__MSG_ic3Action__",
    "default_popup": "popup/week.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{db73f0df-bf4e-421c-8819-6dd1743598cf}"
    }
  }
}