Examine source code of RefineTube

{
  "manifest_version": 2,
  "name": "RefineTube",
  "description": "RefineTube is a browser extension that helps control your YouTube usage by providing AI-powered video ratings.",
  "version": "0.0.1",
  "icons": {
    "16": "icon/16.png",
    "32": "icon/32.png",
    "48": "icon/48.png",
    "96": "icon/96.png",
    "128": "icon/128.png"
  },
  "permissions": [
    "scripting",
    "storage",
    "*://i.ytimg.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "RefineTube",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "run_at": "document_end",
      "js": [
        "content-scripts/content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{4022d463-69f4-4ec5-9db7-0a5bf505e856}"
    }
  }
}