Examine source code of Calender by RT

{
  "name": "Calender by RT",
  "description": "Quickly see the time until your next meeting from any of your calendars",
  "manifest_version": 2,
  "default_locale": "en",
  "options_page": "views/options.html",
  "options_ui": {
    "page": "views/options.html",
    "chrome_style": true
  },
  "version": "2.0.0",
  "background": {
    "scripts": [
      "javascript/background.js"
    ],
    "persistent": false
  },
  "permissions": [
    "notifications"
  ],
  "browser_action": {
    "default_icon": {
      "19": "images/icon-19.png",
      "38": "images/icon-38.png"
    },
    "default_title": "Calender by RT"
  },
  "icons": {
    "16": "images/icon-16.png",
    "48": "images/icon-48.png",
    "128": "images/icon-128.png"
  }
}