Examine source code of Reddit link fixer

{
  "manifest_version": 2,
  "name": "Reddit link fixer",
  "version": "1.0",
  "description": "Makes old.reddit.com or redditmedia.com links open in reddit.com",
  "icons": {
    "48": "icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://old.reddit.com/*",
        "*://redditmedia.com/*"
      ],
      "js": [
        "reddit-link-fixer.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{737aa347-3a8a-462f-b9bc-a971fbfa9c8a}"
    }
  }
}