Examine source code of rickrolln't

{
  "manifest_version": 2,
  "name": "rickrolln't",
  "author": "colenh",
  "short_name": "rickrolln't",
  "version": "1.3.0",
  "description": "redirects rickrolls and more to a diffferent page",
  "icons": {
    "512": "rickrollnt.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "*://youtube.com/*",
    "*://*.youtube.com/*",
    "*://*.thisworldthesedays.com/*",
    "*://*.noordstar.me/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{7e52e1e6-693b-4301-ae99-4c91bf2a1dd6}"
    }
  }
}