Examine source code of Nitter Instead

{
  "name": "Nitter Instead",
  "description": "Use Nitter instead of Twitter.",
  "version": "2.6",
  "manifest_version": 2,
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "256": "nitter_instead.png"
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "*://*.twitter.com/*"
  ]
}