Examine source code of Leetcode Contest Tracker

{
  "manifest_version": 3,
  "name": "Contest Tracker: Leetcode",
  "version": "0.1.1",
  "description": "Leetcode Contest Performance Tracker",
  "icons": {
    "128": "icon1.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "shubhamojha4444@gmail.com"
    }
  },
  "permissions": [
    "tabs",
    "activeTab",
    "storage",
    "scripting"
  ],
  "action": {
    "default_icon": "icon1.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://leetcode.com/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ]
}