Examine source code of GrindMap

{
  "manifest_version": 2,
  "name": "GrindMap",
  "version": "1.0.0",
  "applications": {
    "gecko": {
      "id": "grindmap@example.com",
      "strict_min_version": "58.0"
    }
  },
  "description": "Track your LeetCode daily streak and visualize it in a beautiful heatmap. Stay motivated and keep grinding!",
  "permissions": [
    "tabs",
    "storage",
    "notifications",
    "alarms",
    "*://leetcode.com/*",
    "*://www.leetcode.com/*"
  ],
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://leetcode.com/*",
        "*://www.leetcode.com/*",
        "*://*.leetcode.com/*",
        "https://leetcode.com/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "content.css"
      ],
      "run_at": "document_start",
      "all_frames": true
    }
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "GrindMap - Track Your LeetCode Streak",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "options_page": "options.html",
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  }
}