TabSub: Serverless PubSub for Browser Tabs

TabSub is a lightweight Javascript library for publishing and subscribing to messages between browser tabs using local storage. No server is required. It provides a simple API with `publish`, `subscribe`, and `state` functions. While not heavily tested for concurrency, small-scale tests showed promising results. TabSub is MIT licensed and available on Github. An example demonstrates syncing the playback state of two audio players.