Examine source code of Multi engine search

{
  "manifest_version": 2,
  "name": "Multi engine search",
  "version": "1.1",
  "description": "Search on Multiple search engines.",
  "homepage_url": "https://github.com/Javojav/Multi-engine-search",
  "icons": {
    "48": "icons/icon.png"
  },
  "permissions": [
    "search"
  ],
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Ctrl+Shift+L"
      }
    }
  },
  "browser_action": {
    "default_icon": "icons/icon.png",
    "default_title": "Multi engine search",
    "default_popup": "popup/search.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{c2278bd8-d59c-4c4b-b637-c8872eeed658}"
    }
  }
}