Examine source code of PassGrinder

{
  "name": "PassGrinder",
  "description": "Generate twenty-character strong passwords from your master password and the domain name or unique phrase you choose.",
  "version": "0.0.6",
  "manifest_version": 3,
  "permissions": [
    "tabs"
  ],
  "action": {
    "default_icon": {
      "16": "/images/passgrinder-16.png",
      "32": "/images/passgrinder-32.png",
      "48": "/images/passgrinder-48.png",
      "128": "/images/passgrinder-128.png"
    },
    "default_popup": "index.html"
  },
  "icons": {
    "16": "/images/passgrinder-16.png",
    "32": "/images/passgrinder-32.png",
    "48": "/images/passgrinder-48.png",
    "128": "/images/passgrinder-128.png"
  },
  "web_accessible_resources": [
    {
      "resources": [
        "images/*",
        "js/*",
        "css/*"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "mechobba@gmail.com"
    }
  }
}