Examine source code of Shepherd

{
  "manifest_version": 2,
  "name": "Shepherd",
  "description": "Een extensie voor digibeten, door digiweten",
  "version": "2.1",
  "browser_action": {
    "default_icon": {
      "16": "img/logo16.png",
      "32": "img/logo32.png",
      "48": "img/logo48.png",
      "128": "img/logo128.png"
    },
    "default_popup": "popup.html"
  },
  "icons": {
    "16": "img/logo16.png",
    "32": "img/logo32.png",
    "48": "img/logo48.png",
    "128": "img/logo128.png"
  },
  "permissions": [
    "activeTab",
    "cookies",
    "http://*/*",
    "https://*/*",
    "tabs",
    "notifications",
    "storage"
  ],
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "js/content.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "img/*",
    "css/*.css"
  ]
}