Examine source code of Panic Button

{
  "manifest_version": 2,
  "name": "Panic Button",
  "version": "1.0.3.4",
  "description": "A one-press escape hatch: silence and pause every playing tab, pop open a plausible spreadsheet page, and optionally minimize the window — all from a keyboard shortcut or the toolbar. Undo the mute anytime.",
  "icons": {
    "32": "graphics/icon-32.png",
    "48": "graphics/icon-48.png",
    "64": "graphics/icon-64.png",
    "96": "graphics/icon-96.png",
    "128": "graphics/icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{0266e7c7-d101-4f76-9a8a-300a795dce70}",
      "strict_min_version": "101.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "tabs",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "app/background.js"
    ]
  },
  "commands": {
    "panic": {
      "suggested_key": {
        "default": "Alt+Shift+P"
      },
      "description": "Panic: mute, pause & hide"
    }
  },
  "browser_action": {
    "default_title": "Panic Button",
    "default_popup": "app/popup.html",
    "default_icon": {
      "32": "graphics/icon-32.png",
      "48": "graphics/icon-48.png",
      "64": "graphics/icon-64.png"
    }
  }
}