Examine source code of 5 Second Refresher

{
  "manifest_version": 2,
  "name": "Refresher",
  "version": "1.2",
  "description": "Automatically refreshes the page every few seconds",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "icons/Forget-dark.svg",
    "default_title": "Auto refresh this tab",
    "theme_icons": [
      {
        "light": "icons/Forget-light.svg",
        "dark": "icons/Forget-dark.svg",
        "size": 32
      }
    ]
  },
  "permissions": [
    "activeTab"
  ]
}