Examine source code of Unlock Medium article

{
  "description": "Unlocks Medium articles",
  "manifest_version": 2,
  "name": "Fredium",
  "version": "2.0",
  "icons": {
    "256": "logo.png"
  },
  "permissions": [
    "scripting",
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "http://medium.com/"
      ],
      "js": []
    }
  ],
  "background": {
    "scripts": [
      "fredium.js"
    ]
  },
  "browser_action": {
    "default_icon": "logo.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{78bf203b-51b1-425c-9500-dbc2a0e9cf4d}"
    }
  }
}