Zulip Floating Windows per Divyanshu Agrawal

Enables floating narrows in Zulip, so that you can chat in multiple places at the same time without losing your location, in the same tab.

# Features

* Supports multiple floating windows.
* Floating windows are movable.
* Minimize/ maximize the windows to save space.
* Window themed according to Zulip dark mode setting.

## How to use

Alt+Click on narrow headers to use. Narrow headers look like 'general > welcome to zulip' bars in your message list.

See https://github.com/agrawal-d/zulip-floating-windows#how-to-use for a GIF on how to use.