Examine source code of X-tra Features

{
  "manifest_version": 3,
  "name": "X-tra Features",
  "description": "Enhance X.com analytics with full-width graphs and calculated followers timeline",
  "version": "1.2.0",
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "xtra-features@extension",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://x.com/*",
        "https://twitter.com/*"
      ],
      "js": [
        "lib/chart.min.js",
        "src/utils.js",
        "src/followers-chart.js",
        "src/best-time.js",
        "src/char-counter.js",
        "src/content.js"
      ],
      "css": [
        "src/content.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "lib/chart.min.js"
      ],
      "matches": [
        "https://x.com/*",
        "https://twitter.com/*"
      ]
    }
  ]
}