Examine source code of Audio Transposer

{
  "manifest_version": 2,
  "name": "Audio Transposer",
  "version": "2.3.3",
  "description": "Transpose audio pitch up and down by musical intervals",
  "author": "Sait",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "permissions": [
    "activeTab",
    "storage",
    "tabs"
  ],
  "browser_action": {
    "default_icon": {
      "48": "icons/icon-48.png"
    },
    "default_title": "Audio Transposer",
    "default_popup": "popup/popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content/content.js"
      ],
      "run_at": "document_end"
    }
  ],
  "background": {
    "scripts": [
      "background/background.js"
    ]
  },
  "web_accessible_resources": [
    "content/pitch-worklet.js",
    "content/spotify-bridge.js"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "jpgw2hrhex@addons.mozilla.org",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  }
}