Examine source code of Jisho Searcher

{
  "manifest_version": 2,
  "name": "Jisho Searcher",
  "version": "1.0",
  "description": "Searches text in jisho",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png"
  },
  "permissions": [
    "menus"
  ]
}