add(README): quick links to documentation
<img src="https://raw.githubusercontent.com/zellij-org/zellij/main/assets/demo.gif" alt="demo">
</p>
+<h4 align="center">
+ [<a href="https://zellij.dev/documentation/installation">Installation</a>]
+ [<a href="https://zellij.dev/documentation/overview">Overview</a>]
+ [<a href="https://zellij.dev/documentation/configuration">Configuration</a>]
+ [<a href="https://zellij.dev/documentation/layouts-templates">Templates</a>]
+ [<a href="https://zellij.dev/documentation/faq">FAQ</a>]
+</h4>
# What is this?
