Introducing mamba Guru on Gurubase.io (#3612)

Signed-off-by: Kursat Aktas <kursat.ce@gmail.com>

README.md

@@ -21,6 +21,7 @@
 [![Build Status](https://github.com/mamba-org/mamba/workflows/CI/badge.svg)](https://github.com/mamba-org/mamba/actions)
 [![Join the Gitter Chat](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/mamba-org/Lobby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 [![docs](https://readthedocs.org/projects/mamba/badge/?version=latest&style=flat)](https://mamba.readthedocs.io/en/latest)
+[![Gurubase](https://img.shields.io/badge/Gurubase-Ask%20mamba%20Guru-006BFF)](https://gurubase.io/g/mamba)
 
 `mamba` is a reimplementation of the conda package manager in C++.