Examine source code of Purple Leetcode

{
  "manifest_version": 3,
  "name": "LeetCode Purple",
  "version": "1.0.0",
  "description": "Turns the green heatmap squares on your LeetCode profile to purple.",
  "icons": {
    "48": "icons/purpleleetcode48.jpg",
    "96": "icons/purpleleetcode96.jpg",
    "128": "icons/purpleleetcode128.jpg"
  },
  "content_scripts": [
    {
      "matches": [
        "*://leetcode.com/*"
      ],
      "js": [
        "content/index.js"
      ],
      "css": [
        "styles/theme-purple.css",
        "styles/theme-blue.css",
        "styles/theme-green.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "action": {
    "default_popup": "popup/index.html"
  },
  "permissions": [
    "storage",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "lc-purple@dev",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  }
}