Rendering a UI

When a plugin's render function prints to STDOUT, Zellij treats the printed bytes as utf-8 ANSI. One can print to a Zellij plugin just like one could print to any terminal and have it rendered, with the following exception:

Every time the render function is called, the previous state of the terminal is cleared. This is in order to facilitate UI development without having to keep track of the previous state on screen. This behavior might be toggleable in the future.

Plugin developers are free to use whichever terminal UI libraries they wish in order to render a Zellij plugin. In the future Zellij might offer a UI library of its own as well as an integration with a few popular ones.