Examine source code of CSS Layout Debugger

{
  "manifest_version": 2,
  "name": "CSS Layout Debugger",
  "version": "1.0.0",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "developer": {
    "name": "Vince Picone",
    "url": "https://vincepic.one"
  },
  "description": "Adds dynamic backgrounds and outlines to assist layout debugging.",
  "icons": {
    "48": "icons/active.svg",
    "96": "icons/active.svg"
  },
  "browser_action": {
    "default_title": "Favourite colour option",
    "default_icon": "icons/inactive.svg"
  },
  "permissions": [
    "activeTab"
  ]
}