Examine source code of TuneShift

{
  "manifest_version": 3,
  "name": "TuneShift",
  "version": "0.1.0",
  "description": "Real-time YouTube semitone pitch shifting for instrument practice.",
  "icons": {
    "16": "assets/icons/icon-16.png",
    "32": "assets/icons/icon-32.png",
    "48": "assets/icons/icon-48.png",
    "128": "assets/icons/icon-128.png"
  },
  "permissions": [
    "activeTab"
  ],
  "host_permissions": [
    "https://www.youtube.com/*"
  ],
  "action": {
    "default_title": "TuneShift",
    "default_popup": "popup.html",
    "default_icon": {
      "16": "assets/icons/icon-16.png",
      "32": "assets/icons/icon-32.png",
      "48": "assets/icons/icon-48.png",
      "128": "assets/icons/icon-128.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.youtube.com/*"
      ],
      "js": [
        "lib/tuneshift-core.js",
        "lib/tuneshift-audio-engine.js",
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "pitch/worklet/index.js",
        "pitch/worklet/SoundTouchNode.js",
        "pitch/worklet/constants.js",
        "pitch/worklet/soundtouch-processor.js",
        "pitch/worklet/SOUNDTOUCH-WORKLET-LICENSE.txt"
      ],
      "matches": [
        "https://www.youtube.com/*"
      ]
    }
  ],
  "background": {
    "scripts": [
      "lib/tuneshift-core.js",
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "tuneshift@tuneshift.local",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}