Examine source code of Manga Reader

{
  "manifest_version": 2,
  "name": "Manga Reader",
  "version": "2.2",
  "description": "View all images on a page one at a time.",
  "permissions": [
    "activeTab",
    "tabs",
    "<all_urls>",
    "storage"
  ],
  "icons": {
    "16": "icons/icon.svg",
    "32": "icons/icon.svg",
    "48": "icons/icon.svg",
    "128": "icons/icon.svg"
  },
  "browser_action": {
    "default_icon": {
      "16": "icons/icon.svg",
      "32": "icons/icon.svg",
      "48": "icons/icon.svg",
      "128": "icons/icon.svg"
    },
    "default_title": "Manga Reader",
    "default_popup": "popup.html"
  },
  "web_accessible_resources": [
    "style.css"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "commands": {
    "launch-manga-reader": {
      "suggested_key": {
        "default": "Alt+R",
        "mac": "MacCtrl+R"
      },
      "description": "Launch Manga Reader"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{aace4723-65de-411a-93c7-91395447feee}"
    }
  }
}