Examine source code of Document delivery icon

{
  "manifest_version": 2,
  "name": "Document delivery icon",
  "version": "1.0",
  "description": "The document delivery icon is commonly used to represent the action of sharing, submitting, transferring, or sending a document from one person to another in digital applications (e.g. document management, learning, work).",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html",
    "default_title": "Click me!"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{31e562a5-50d9-41aa-a5fe-e5d0b443ffa1}"
    }
  }
}