Examine source code of Tab Audio Controller

{
  "manifest_version": 3,
  "name": "Tab Audio Controller",
  "version": "1.0.0",
  "description": "Control and amplify HTML media volume per browser tab.",
  "permissions": [
    "tabs"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "icons": {
    "48": "src/icon.svg",
    "96": "src/icon.svg"
  },
  "background": {
    "scripts": [
      "src/background.js"
    ]
  },
  "action": {
    "default_icon": "src/icon.svg",
    "default_title": "Tab Audio Controller",
    "default_popup": "src/popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "src/audio/media-controller.js",
        "src/content.js"
      ],
      "run_at": "document_idle",
      "all_frames": true
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "tab-audio-controller@hmmburger",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "strict_min_version": "140.0"
    }
  }
}