Examine source code of Text Highlighter

{
  "manifest_version": 2,
  "name": "Text Highlighter",
  "description": "This extension allows you to highlight text on any website.",
  "version": "1.0",
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "js": [
        "content.js"
      ],
      "matches": [
        "<all_urls>"
      ],
      "run_at": "document_end"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{3d082eec-7a27-4ca4-bded-5fcb48015e93}"
    }
  }
}