Examine source code of RickRollProtector

{
  "manifest_version": 2,
  "name": "RickRollProtector",
  "description": "__MSG_manifestDesc__",
  "version": "2.0.0.0",
  "icons": {
    "16": "icons/16.png",
    "32": "icons/32.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "developer": {
    "name": "fab3F",
    "url": "https://fab3F.github.io"
  },
  "default_locale": "en",
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "rickrollprotector@fab3F.github.io",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "web_accessible_resources": [
    "error.html"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://fab3f.github.io/rickrollprotector/*"
      ],
      "run_at": "document_idle",
      "js": [
        "content-scripts/website.js"
      ]
    },
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "run_at": "document_start",
      "js": [
        "content-scripts/youtube.js"
      ]
    }
  ]
}