Examine source code of Tranquility Lite Reader by pp4mnk

{
  "manifest_version": 2,
  "name": "Tranquility Lite Reader",
  "version": "2.2",
  "description": "Improves the readability of web articles by stripping distractions and applying a clean, customizable reader mode.",
  "icons": {
    "48": "icons/book-48.png",
    "96": "icons/book-96.png"
  },
  "permissions": [
    "activeTab",
    "storage",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Toggle Tranquility Lite Reader",
    "default_icon": {
      "48": "icons/book-48.png",
      "96": "icons/book-96.png"
    }
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "tranquility-lite-reader@example.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}