Examine source code of Reddit Subdomain Redirect

{
  "manifest_version": 2,
  "name": "Reddit Subdomain Redirect",
  "version": "1.0",
  "description": "Redirects reddit subdomains to their corresponding subreddits on old.reddit.com",
  "homepage_url": "https://github.com/yourusername/subreddit-subdomain-redirect",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "*://*.reddit.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "applications": {
    "gecko": {
      "id": "reddit-subdomain-redirect@yourdomain.com"
    }
  }
}