Examine source code of Oldify

{
  "manifest_version": 2,
  "name": "Oldify",
  "version": "1.0",
  "description": "Automatically redirects to old Reddit whenever it detects that you aren't there already.",
  "content_scripts": [
    {
      "matches": [
        "*://*.reddit.com/*"
      ],
      "js": [
        "oldify.js"
      ]
    }
  ]
}