Examine source code of leetcode-shortcut

{
  "manifest_version": 2,
  "name": "leetcode-shortcuts",
  "version": "1.13.1.4",
  "description": "leetcode shortcuts",
  "icons": {
    "48": "icons/leetcode_logo.png"
  },
  "browser_action": {
    "default_icon": "icons/leetcode_logo.png",
    "default_title": "Leetcode shortcuts",
    "default_popup": "shortcut.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.leetcode.com/*"
      ],
      "js": [
        "shortcut.js"
      ],
      "css": [
        "shortcut.css"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{b50bf646-0b0e-4379-9f63-d5c7e54f965d}"
    }
  }
}