Examine source code of GeoCities Time Machine

{
  "manifest_version": 2,
  "name": "GeoCities Time Machine",
  "version": "1.0",
  "description": "Transform any website into a glorious 1990s GeoCities masterpiece",
  "homepage_url": "https://github.com/sugardaddyapp/geocities-firefox-extension",
  "developer": {
    "name": "Best Sugar Daddy App",
    "url": "https://bestsugardaddyapps.com"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "geocities-time-machine@bestsugardaddyapps.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "permissions": [
    "activeTab",
    "storage",
    "tabs"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "content.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png"
  }
}