Examine source code of WikiMapper

{
  "manifest_version": 3,
  "name": "WikiMapper",
  "description": "WikiMapper - Track and graph your adventures down the Wikipedia rabbit hole.",
  "version": "3.0.4",
  "icons": {
    "19": "resources/wikimapper-19.png",
    "38": "resources/wikimapper-38.png",
    "48": "resources/wikimapper-48.png",
    "128": "resources/wikimapper-128.png"
  },
  "author": "Patrick McCarthy",
  "homepage_url": "http://www.github.com/ptmccarthy/wikimapper",
  "background": {
    "scripts": [
      "background.js"
    ],
    "type": "module"
  },
  "permissions": [
    "webNavigation",
    "storage"
  ],
  "action": {
    "default_title": "WikiMapper",
    "default_icon": "resources/wikimapper-38.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "wikimapper-ff@ptmccarthy.github.io",
      "strict_min_version": "109.0"
    }
  }
}