Examine source code of Pronunciation Helper

{
  "manifest_version": 2,
  "name": "Pronunciation Helper",
  "version": "1.0",
  "permissions": [
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "images/icon16.svg",
      "48": "images/icon48.svg",
      "128": "images/icon128.svg"
    }
  },
  "icons": {
    "16": "images/icon16.svg",
    "48": "images/icon48.svg",
    "128": "images/icon128.svg"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{dc953b99-17cc-4bc7-bbd3-5055ea9cc0f1}"
    }
  }
}