Examine source code of Fetch A Word

{
  "manifest_version": 2,
  "name": "Fetch A Word",
  "version": "1.0",
  "description": "Transform your reading experience with instant word definitions! Simply double-click any english word while browsing to reveal its dictionary meaning in a small popup. A great tool for those who love expanding their vocabulary while browsing the web.",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{8c3fbd12-34a5-67e8-90bc-def123456789}"
    }
  },
  "permissions": [
    "activeTab",
    "https://api.dictionaryapi.dev/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_end"
    }
  ]
}