Examine source code of Floating Player Plus

{
  "manifest_version": 2,
  "name": "Floating Player Plus",
  "version": "1.3",
  "description": "Play any video in a floating always-on-top window (Picture-in-Picture style) with extra controls.",
  "permissions": [
    "tabs",
    "activeTab",
    "storage",
    "<all_urls>"
  ],
  "browser_action": {
    "default_title": "Floating Player Plus",
    "default_popup": "popup.html",
    "default_icon": {
      "32": "icons/logo_32.png",
      "64": "icons/logo_64.png",
      "128": "icons/logo_128.png"
    }
  },
  "icons": {
    "32": "icons/logo_32.png",
    "64": "icons/logo_64.png",
    "128": "icons/logo_128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "commands": {
    "toggle-floating-player": {
      "suggested_key": {
        "default": "Alt+P"
      },
      "description": "Toggle Floating Player"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{be4d1c83-f69f-454d-a38a-5eba699a86e7}"
    }
  }
}