Examine source code of LibJS Detector

{
  "manifest_version": 2,
  "name": "LibJS Detector",
  "short_name": "Library Detector for Firefox",
  "version": "1.1.1",
  "web_accessible_resources": [
    "library/libraries.js",
    "content_scripts/lib_detect.js"
  ],
  "description": "Detects the Javascript libraries running on a page and displays their icons in the address bar.",
  "icons": {
    "48": "iconext/icon48.png",
    "128": "iconext/icon128.png"
  },
  "background": {
    "scripts": [
      "library/libraries.js",
      "background_scripts/main.js"
    ]
  },
  "page_action": {
    "default_icon": {
      "19": "iconext/icon19.png",
      "38": "iconext/icon38.png"
    },
    "default_title": "LibJS Detector"
  },
  "permissions": [
    "tabs",
    "http://*/*",
    "https://*/*"
  ],
  "applications": {
    "gecko": {
      "id": "@libjsdetector",
      "strict_min_version": "57.0"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "content_scripts/inject.js"
      ],
      "run_at": "document_end"
    },
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "content_scripts/detect.js"
      ],
      "run_at": "document_idle"
    }
  ]
}