Examine source code of Easy Gallery

{
  "manifest_version": 2,
  "name": "Easy Gallery",
  "version": "1.3",
  "description": "View all images on any webpage as a clean gallery overlay",
  "permissions": [
    "activeTab",
    "storage",
    "tabs",
    "<all_urls>",
    "downloads"
  ],
  "commands": {
    "toggle-gallery": {
      "suggested_key": {
        "default": "Ctrl+G"
      },
      "description": "Toggle the page gallery"
    }
  },
  "browser_action": {
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png",
      "96": "icons/icon96.png"
    },
    "default_title": "Open Image Gallery"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "96": "icons/icon96.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "nbanning@pm.me",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}