Examine source code of Onion Location Detector

{
  "manifest_version": 3,
  "name": "Onion Location Detector",
  "version": "2.2",
  "description": "Shows an icon when a site offers an Onion-Location.",
  "author": "Leprechaun - github.com/Leproide",
  "permissions": [
    "webRequest",
    "tabs"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "onion-detector@leproide.github.io",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "48": "icons/onion-active-48.png",
    "96": "icons/onion-active-96.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_icon": {
      "16": "icons/onion-inactive-16.png",
      "32": "icons/onion-inactive-32.png"
    },
    "default_title": "No .onion site available",
    "default_area": "navbar"
  }
}