Examine source code of fortune-browser-extension

{
  "manifest_version": 3,
  "name": "fortune",
  "short_name": "fortune",
  "description": "insightful quote every time you open a new tab.",
  "version": "0.7.0",
  "browser_specific_settings": {
    "gecko": {
      "id": "senthil@uthcode.com"
    }
  },
  "permissions": [
    "tabs"
  ],
  "host_permissions": [
    "*://quotes-1271.appspot.com/*",
    "http://quotes-1271.appspot.com/json",
    "https://fonts.googleapis.com/*"
  ],
  "icons": {
    "16": "assets/img/icon16.png",
    "48": "assets/img/icon48.png",
    "128": "assets/img/icon128.png"
  },
  "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'self'"
  },
  "homepage_url": "https://github.com/orsenthil/fortune-browser-extension",
  "chrome_url_overrides": {
    "newtab": "fortune.html"
  },
  "action": {
    "default_title": "",
    "default_icon": "assets/img/icon256.png"
  }
}