Examine source code of CO2estimeter

{
  "description": "Web extension for estimating the CO2 emissions of browsing activity",
  "version": "1.0.6",
  "name": "CO2estimeter",
  "manifest_version": 3,
  "permissions": [
    "tabs",
    "storage"
  ],
  "icons": {
    "48": "assets/dot_icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "co2estimeter@webextension",
      "strict_min_version": "112.0"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "js/content.bundle.js"
      ],
      "world": "ISOLATED",
      "run_at": "document_start",
      "all_frames": true
    }
  ],
  "background": {
    "scripts": [
      "js/background.bundle.js"
    ],
    "type": "module"
  },
  "action": {
    "default_title": "CO2estimeter",
    "default_popup": "popup.html",
    "default_area": "navbar",
    "default_icon": {
      "16": "assets/dot_icon.png",
      "32": "assets/dot_icon.png"
    }
  }
}