Examine source code of Widen Moodle

{
  "manifest_version": 2,
  "name": "Widen Moodle",
  "version": "1.3",
  "description": "Changes a number of Moodle design elements to make better use of space.",
  "icons": {
    "48": "icons/widenmoodle-48.png",
    "96": "icons/widenmoodle-96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "widenmoodle.js"
      ],
      "run_at": "document_end"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{c76e5046-884b-4eb5-8be7-12130c54fb04}"
    }
  }
}