Examine source code of Learnword

{
  "manifest_version": 3,
  "name": "Learnword",
  "version": "0.1.1",
  "description": "A browser extension to help you learn new words while browsing the web.",
  "icons": {
    "16": "icons/icon-16.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png",
    "256": "icons/icon-256.png"
  },
  "action": {
    "default_title": "Learnword",
    "default_popup": "popup/popup.html",
    "default_icon": {
      "16": "icons/icon-16.png",
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    }
  },
  "permissions": [
    "storage",
    "activeTab",
    "scripting",
    "contextMenus",
    "tabs"
  ],
  "host_permissions": [
    "https://api.dictionaryapi.dev/*",
    "https://www.dictionaryapi.com/*",
    "https://api.wordnik.com/*",
    "https://api.mymemory.translated.net/*",
    "https://translation.googleapis.com/*",
    "https://media.merriam-webster.com/*",
    "https://en.wikipedia.org/*",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "service/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "content/content.js"
      ],
      "css": [
        "content/content.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "content/content.css",
        "icons/*",
        "pdf-viewer/dist/index.html",
        "pdf-viewer/dist/assets/*"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "options_ui": {
    "open_in_tab": true,
    "page": "settings/options.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "learnword@learnword.org",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}