Examine source code of ProfitRoom Reservation Card Helper

{
  "manifest_version": 2,
  "name": "Hotel Reservation Card Helper",
  "version": "1.0",
  "description": "Adds guest name and room number to Profitroom reservation cards and highlights BN rates",
  "browser_specific_settings": {
    "gecko": {
      "id": "hotel-reservation-helper@example.com",
      "strict_min_version": "60.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "activeTab",
    "https://mailer.profitroom.net/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://mailer.profitroom.net/pl/preview/crs/hotel*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "styles.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_action": {
    "default_icon": "icon.png",
    "default_title": "Hotel Reservation Helper",
    "default_popup": "popup.html"
  },
  "icons": {
    "48": "icon.png"
  }
}