Examine source code of Click Sound FX

{
  "manifest_version": 2,
  "name": "Click Sound FX",
  "version": "1.0",
  "description": "Phát hiệu ứng âm thanh khi bạn click, gõ phím, cuộn chuột, mở tab...",
  "permissions": [
    "tabs",
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "sounds/*.mp3"
  ],
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d89fbf90-eae7-4bc4-94de-c01cef55457d}"
    }
  }
}