Examine source code of vk-map-icon

{
  "manifest_version": 2,
  "name": "vk-map-icon",
  "version": "1.0",
  "icons": {
    "16": "images/icon_16.png",
    "32": "images/icon_32.png",
    "48": "images/icon_48.png",
    "64": "images/icon_64.png",
    "128": "images/icon_128.png"
  },
  "background": {
    "scripts": [
      "content_scripts/background.js"
    ],
    "persistent": false
  },
  "permissions": [
    "https://vadimklimenko.com/map"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{f886e432-1374-4d01-9618-2d6ed4b74299}"
    }
  }
}