Examine source code of CourseSel

{
  "description": "__MSG_extensionDescription__",
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "version": "1.2",
  "homepage_url": "https://github.com/fxpar/courseSel/",
  "default_locale": "en",
  "icons": {
    "48": "icons/Moodle48.png"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "icons/Moodle32.png",
    "theme_icons": [
      {
        "light": "icons/Moodle32.png",
        "dark": "icons/Moodle32.png",
        "size": 32
      }
    ],
    "default_title": "CourseSel",
    "default_popup": "popup/redirect.html"
  },
  "web_accessible_resources": [
    "icons/*.jpg"
  ]
}