Examine source code of Window Merger

{
  "name": "Window Merger",
  "version": "0.7.3",
  "description": "Options to merge browser windows into one",
  "icons": {
    "16": "assets/icon016.png",
    "24": "assets/icon024.png",
    "32": "assets/icon032.png"
  },
  "developer": {
    "name": "Martijn van der Ven",
    "url": "https://vanderven.se/martijn/"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "type": "module"
  },
  "commands": {
    "merge-all-windows": {
      "description": "Merge all windows into the current one."
    },
    "merge-previous-window": {
      "description": "Merge previously focused window into the current one."
    }
  },
  "manifest_version": 3,
  "options_ui": {
    "page": "preferences.html"
  },
  "permissions": [
    "tabs",
    "menus",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{a116b6c7-0611-4938-ba3d-2e4c61241128}",
      "strict_min_version": "112.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}