Examine source code of Reddit Comment Collapser

{
  "version": "5.1.2resigned1",
  "applications": {
    "gecko": {
      "id": "{a5b2e636-07e5-4331-93c1-6cf4074356c8}",
      "strict_min_version": "42.0"
    }
  },
  "manifest_version": 2,
  "minimum_chrome_version": "41.0.2272.76",
  "name": "Reddit Comment Collapser",
  "description": "A more elegant solution for collapsing reddit comment trees",
  "icons": {
    "48": "image/icon48.png",
    "128": "image/icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "http://*.reddit.com/*/comments/*",
        "https://*.reddit.com/*/comments/*"
      ],
      "css": [
        "css/comment-collapser.css"
      ],
      "js": [
        "js/comment-collapser.js"
      ],
      "run_at": "document_start"
    }
  ],
  "web_accessible_resources": [
    "image/collapse.png",
    "image/collapse-dark.png",
    "image/expand.png",
    "image/expand-dark.png",
    "image/colours/*"
  ],
  "permissions": [
    "storage",
    "https://*.reddit.com/"
  ],
  "options_ui": {
    "page": "views/options.html",
    "chrome_style": true
  }
}