Examine source code of LeetBrawls

{
  "name": "LeetBrawls",
  "description": "The only way to compete with your friends and conquer coding questions",
  "version": "1.0.9",
  "manifest_version": 2,
  "browser_action": {
    "default_popup": "index.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "admin@leetbattles.com",
      "strict_min_version": "54.0a1"
    }
  },
  "icons": {
    "16": "leetbattles_16.png",
    "48": "leetbattles_48.png",
    "128": "leetbattles_128.png"
  },
  "permissions": [
    "tabs",
    "storage",
    "identity",
    "webRequest",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "./static/js/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://*.leetcode.com/problems/*"
      ],
      "js": [
        "./static/js/content.js"
      ],
      "css": [
        "/static/css/content.css"
      ]
    }
  ],
  "content_security_policy": "script-src 'self'; object-src 'self';"
}