Examine source code of Convert to UTF-8

{
  "manifest_version": 2,
  "name": "Convert to UTF-8",
  "description": "Add a context menu option to convert to UTF-8",
  "version": "1.0",
  "homepage_url": "https://github.com/mdn",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "16": "icons/fred.svg",
    "32": "icons/fred.svg"
  },
  "permissions": [
    "activeTab",
    "contextMenus",
    "clipboardWrite"
  ]
}