Examine source code of Search for Image

{
  "name": "Search for Image",
  "description": "Adds an item to the context menu of images to perform a reverse image search using the most popular search engines.",
  "version": "1.0.0",
  "manifest_version": 2,
  "icons": {
    "16": "images/icon-all_sizes.svg",
    "32": "images/icon-all_sizes.svg",
    "48": "images/icon-all_sizes.svg",
    "64": "images/icon-all_sizes.svg",
    "96": "images/icon-all_sizes.svg",
    "128": "images/icon-all_sizes.svg"
  },
  "permissions": [
    "contextMenus"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}