Examine source code of Page Tinker

{
  "manifest_version" : 3 ,
  "name" : "Page Tinker",
  "version" : "0.4.0",
  "description" : "Click any element to edit its text, hide it, or delete it - no DevTools needed. Undo/redo supported. Changes reset on reload.",
  "author": "HalfToast",
  "homepage_url" : "https://github.com/HalfToast/page-tinker",
  "browser_specific_settings": {
    "gecko": {
      "id": "page-tinker@halftoast.dev",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  },
  "permissions" : [
    "activeTab" ,
    "scripting" ,
    "contextMenus" 
  ],
  "background" : {
    "scripts" : [
      "background.js" 
    ]
  },
  "action" : {
    "default_title" : "Toggle Page Tinker",
    "default_icon" : "icon.svg"
  },
  "commands" : {
    "toggle-tinker": {
      "suggested_key": {
        "default": "Alt+Shift+E"
      },
      "description" : "Toggle Page Tinker on the current tab"
    }
  },
  "icons" : {
    "48" : "icon.svg",
    "96" : "icon.svg"
  }
}