Examine source code of Paste for Monaco

{
  "manifest_version": 2,
  "name": "Paste for Monaco",
  "version": "1.0",
  "description": "Brings paste back to a few sites that use Monaco.",
  "icons": {
    "48": "icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://codesandbox.io/*",
        "*://makecode.microbit.org/*",
        "*://next.plnkr.co/edit/*",
        "*://plnkr.co/edit/*",
        "*://playcode.io/*"
      ],
      "js": [
        "script.js"
      ],
      "run_at": "document_start"
    }
  ],
  "permissions": [
    "clipboardRead"
  ]
}