Examine source code of NotesManager

{
  "manifest_version": 2,
  "name": "Notizen-Add-On",
  "version": "1.0",
  "description": "Add-On zum Verwalten von Notizen.",
  "icons": {
    "96": "icons/icon_96.png"
  },
  "permissions": [
    "storage"
  ],
  "action": {
    "default_popup": "index.html",
    "default_icon": {
      "96": "icons/icon_96.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "notes.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{a217da25-13f3-4c41-8a45-a7b575bf5685}"
    }
  }
}