Examine source code of Exercise Deck Builder

{
  "manifest_version": 3,
  "icons": {
    "16": "icon/16.png",
    "32": "icon/32.png",
    "48": "icon/48.png",
    "96": "icon/96.png",
    "128": "icon/128.png"
  },
  "name": "Exercise Deck Builder",
  "description": "Build your own deck of custom exercise cards",
  "permissions": [
    "activeTab",
    "tabs",
    "scripting",
    "storage"
  ],
  "background": {
    "scripts": [
      "src/background.js"
    ]
  },
  "action": {
    "default_popup": "src/popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{b79cbfb4-f1da-47ea-9842-1ebeff3fdf12}"
    }
  },
  "version": "1.2.1"
}