Examine source code of Wikiread

{
  "name": "Wikiread",
  "description": "Read wikipedia pages and rank them to help support data collection for furthering education in Information Retrieval.",
  "version": "1.1",
  "manifest_version": 2,
  "permissions": [
    "storage",
    "tabs",
    "https://cutewiki.charlie.city/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://en.wikipedia.org/wiki/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "css/style.css"
      ],
      "run_at": "document_end"
    }
  ],
  "browser_action": {
    "default_popup": "popup/popup.html",
    "default_icon": {
      "128": "icons/icon.png"
    },
    "default_title": "Wikiread",
    "browser_style": true
  },
  "icons": {
    "128": "icons/icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "charlie.city.wiki@gmail.com"
    }
  },
  "content_security_policy": "script-src 'self' https://cutewiki.charlie.city/*; object-src 'self'",
  "optional_permissions": [
    "https://cutewiki.charlie.city/*"
  ]
}