Examine source code of HN Comment Embiggen

{
  "manifest_version": 2,
  "name": "HN Comments",
  "version": "1.0",
  "description": "Emphasizes comment count on Hacker News posts.",
  "icons": {
    "48": "hn48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://news.ycombinator.com/*"
      ],
      "js": [
        "hn_comments.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{599d70e8-f05f-4104-af61-dd0987ac2429}"
    }
  }
}