Examine source code of Caption Customizer

{
  "manifest_version": 2,
  "name": "Caption Customizer",
  "version": "1.0",
  "description": "Customize video captions on popular video platforms.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_title": "Caption Customizer",
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{228f3a20-e3f2-490c-bee6-6900a0ca1ee9}"
    }
  }
}