Examine source code of Caption Editor

{
  "manifest_version": 2,
  "name": "Caption Editor",
  "version": "1.0",
  "description": "A lightweight tool for basic caption editing.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{07d920ec-e796-44e1-8d5c-93fb729816c2}"
    }
  }
}