Examine source code of Environment Marker

{
  "manifest_version": 3,
  "name": "__MSG_appName__",
  "version": "1.2.1",
  "description": "__MSG_appDescription__",
  "icons": {
    "16": "/images/icon-16.png",
    "32": "/images/icon-32.png",
    "64": "/images/icon-64.png",
    "128": "/images/icon-128.png",
    "256": "/images/icon-256.png",
    "512": "/images/icon-512.png"
  },
  "default_locale": "en",
  "action": {
    "default_icon": {
      "16": "/images/icon-16.png",
      "32": "/images/icon-32.png",
      "64": "/images/icon-64.png",
      "128": "/images/icon-128.png",
      "256": "/images/icon-256.png",
      "512": "/images/icon-512.png"
    },
    "default_title": "Environment Marker",
    "default_popup": "html/popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "scripts/libs/textfit/textFit.min.js",
        "scripts/modal.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "activeTab",
    "storage",
    "alarms"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "options_page": "html/options.html",
  "browser_specific_settings": {
    "gecko": {
      "id": "environmentmarker@example.com",
      "strict_min_version": "109.0"
    }
  }
}