Examine source code of Audiobook Reader

{
  "name": "Audiobook Reader",
  "description": "This extension is designed specially for playing audio books",
  "version": "0.1.0",
  "manifest_version": 2,
  "homepage_url": "https://webextension.org/listing/audiobook-reader.html",
  "permissions": [
    "storage",
    "unlimitedStorage"
  ],
  "background": {
    "scripts": [
      "/v2/chrome.action.js",
      "/v2/chrome.windows.create.js",
      "/v2/chrome.windows.get.js",
      "/v2/chrome.windows.getCurrent.js",
      "worker.js"
    ]
  },
  "icons": {
    "16": "data/window/icons/16.png",
    "32": "data/window/icons/32.png",
    "48": "data/window/icons/48.png",
    "64": "data/window/icons/64.png",
    "128": "data/window/icons/128.png",
    "256": "data/window/icons/256.png",
    "512": "data/window/icons/512.png",
    "1024": "data/window/icons/1024.png"
  },
  "commands": {
    "_execute_browser_action": {}
  },
  "browser_action": {},
  "browser_specific_settings": {
    "gecko": {
      "id": "{c78c6e75-949f-412b-a00a-671b1b54a369}"
    }
  }
}