Examine source code of WillMap

{
  "manifest_version": 3,
  "name": "WillMap",
  "version": "0.2.8",
  "description": "Represents housing data from willhaben.at search results and displays on a map",
  "icons": {
    "16": "icons/map16.png",
    "64": "icons/map64.png",
    "128": "icons/map128.png"
  },
  "action": {
    "default_icon": {
      "16": "icons/map16.png",
      "64": "icons/map64.png",
      "128": "icons/map128.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "activeTab",
    "storage",
    "cookies"
  ],
  "host_permissions": [
    "https://www.willhaben.at/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://www.willhaben.at/*"
      ],
      "js": [
        "leaflet.js",
        "node_modules/leaflet.markercluster/dist/leaflet.markercluster.js",
        "marker.js",
        "willmap.js"
      ],
      "css": [
        "leaflet.css",
        "node_modules/leaflet.markercluster/dist/MarkerCluster.css",
        "node_modules/leaflet.markercluster/dist/MarkerCluster.Default.css",
        "custom.css"
      ]
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "images/*"
      ],
      "matches": [
        "https://www.willhaben.at/*"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "willmap@proton.me"
    }
  }
}