Examine source code of Word Translator Hover

{
  "manifest_version": 2,
  "name": "Word Translator Hover",
  "version": "1.0",
  "description": "Translate words on hover using a tooltip.",
  "icons": {
    "48": "icon.png"
  },
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{01f516dd-d5a6-48d1-a3e9-9c81cb01b554}"
    }
  }
}