Examine source code of MA Grid

{
  "manifest_version": 3,
  "name": "MA Grid",
  "description": "GitHub-style activity graph for Math Academy",
  "version": "1.4.0",
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_title": "MA Grid Settings",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "https://mathacademy.com/learn",
        "https://www.mathacademy.com/learn"
      ],
      "js": [
        "content-scripts/content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      },
      "id": "support@route4.dev"
    }
  }
}