Examine source code of WebSocket Detector

{
  "manifest_version": 2,
  "name": "WebSocket Detector",
  "version": "1.2.4resigned1",
  "description": "Detects websocket connection.",
  "homepage_url": "https://github.com/mbnuqw/ws-detector",
  "icons": {
    "48": "./assets/icons/ws-48.png",
    "96": "./assets/icons/ws-96.png"
  },
  "permissions": [
    "webRequest",
    "tabs",
    "<all_urls>"
  ],
  "page_action": {
    "default_icon": {
      "19": "./assets/icons/ws-16_logo_inact.png",
      "38": "./assets/icons/ws-32_logo_inact.png"
    },
    "default_title": "WebSocket not detected"
  },
  "background": {
    "scripts": [
      "background/main.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{56e31223-86c7-4ea9-bbf1-256a2feeb775}"
    }
  }
}