Examine source code of Reading Time Estimator

{
  "manifest_version": 2,
  "name": "Reading Time Estimator",
  "version": "1.0.0",
  "description": "Displays estimated reading time for web pages based on content analysis and average reading speed",
  "browser_specific_settings": {
    "gecko": {
      "id": "readingtimeestimatorkelohame@example.com"
    }
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "styles.css"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Reading Time Settings"
  },
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  }
}