Examine source code of MaskWord for X

{
  "manifest_version": 3,
  "name": "__MSG_appName__",
  "version": "0.2.0",
  "description": "__MSG_appDescription__",
  "default_locale": "ja",
  "icons": {
    "16": "icons/maskword-16.png",
    "32": "icons/maskword-32.png",
    "48": "icons/maskword-48.png",
    "96": "icons/maskword-96.png",
    "128": "icons/maskword-128.png"
  },
  "permissions": [
    "storage"
  ],
  "host_permissions": [
    "https://x.com/*",
    "https://twitter.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://x.com/*",
        "https://twitter.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "action": {
    "default_title": "__MSG_appName__",
    "default_icon": {
      "16": "icons/maskword-16.png",
      "32": "icons/maskword-32.png",
      "48": "icons/maskword-48.png",
      "96": "icons/maskword-96.png",
      "128": "icons/maskword-128.png"
    },
    "default_popup": "options.html"
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "maskword@example.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "strict_min_version": "140.0"
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  }
}