Examine source code of QuoteMachine

{
  "name": "QuoteMachine",
  "version": "1.3.0",
  "manifest_version": 2,
  "description": "",
  "icons": {
    "16": "images/icon-16.png",
    "128": "images/icon-128.png"
  },
  "default_locale": "en",
  "applications": {
    "gecko": {
      "id": "ff-extension@quotemachine.com",
      "strict_min_version": "75.0"
    }
  },
  "background": {
    "scripts": [
      "scripts/background.js"
    ]
  },
  "permissions": [
    "storage",
    "activeTab",
    "tabs",
    "https://*.lightspeedapp.com/*",
    "https://*.merchantos.com/*",
    "https://*.chronogolf.com/*",
    "https://*.posios.com/*",
    "https://*.qmach.in/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://*.lightspeedapp.com/*",
        "https://*.merchantos.com/*",
        "https://local.qmach.in/*",
        "https://staging.qmach.in/*",
        "https://qmach.in/*"
      ],
      "js": [
        "scripts/contentscript.js"
      ],
      "run_at": "document_end",
      "all_frames": false
    }
  ],
  "content_security_policy": "script-src 'self' 'unsafe-eval'; object-src 'self'",
  "browser_action": {
    "default_icon": {
      "19": "images/icon-19.png",
      "38": "images/icon-38.png"
    },
    "default_title": "QuoteMachine extension",
    "default_popup": "popup.html"
  }
}