Examine source code of Scroll To Top - Lite

{
  "name": "Scroll To Top - Lite",
  "version": "1.0",
  "manifest_version": 2,
  "description": "Light weight Scroll to Top/Bottom extension.",
  "homepage_url": "https://github.com/pratikabu/scrolltotop-lite",
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "icons": {
    "16": "icons/sttl-icon-16.png",
    "24": "icons/sttl-icon-24.png",
    "32": "icons/sttl-icon-32.png",
    "48": "icons/sttl-icon-48.png",
    "64": "icons/sttl-icon-64.png",
    "128": "icons/sttl-icon-128.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "icons/sttl-icon-16.png",
      "24": "icons/sttl-icon-24.png",
      "32": "icons/sttl-icon-32.png"
    },
    "default_title": "Scroll to Top/Bottom in a page"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "scrolltotop-lite@pratikabu"
    }
  }
}