Examine source code of Ultimate Knife Kit

{
  "name": "Ultimate Knife Kit",
  "description": "this extension is about website http://ultimateknifekit.com/",
  "version": "0.0.0.1",
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "permissions": [],
  "browser_action": {},
  "manifest_version": 2,
  "icons": {
    "128": "logo.png"
  }
}