Examine source code of Milk icon

{
  "manifest_version": 2,
  "name": "Milk icon",
  "version": "1.0",
  "description": "The milk symbol is used to represent a healthy, nutritious drink, a symbol of purity, simplicity, and cleanliness, used in contexts of diet, health, breakfast, or healthy eating habits.",
  "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": "{4ed5862f-54f3-4202-ac37-895cc9ff51ba}"
    }
  }
}