Examine source code of Hide my MFA codes

{
  "manifest_version": 2,
  "name": "Hide my MFA codes",
  "description": "Hides MFA codes from prying eyes.",
  "version": "1.0.2",
  "author": "Jeroen Swen",
  "icons": {
    "96": "icons/icon-96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "js/main.js"
      ],
      "all_frames": true,
      "run_at": "document_start"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{faae068b-e4a1-42d6-bb8a-4f7aedffd737}"
    }
  }
}