Activated the new "extremos" documentation

README.md

@@ -2,7 +2,7 @@
 
 urbs is a [linear programming](https://en.wikipedia.org/wiki/Linear_programming) optimisation model for capacity expansion planning and unit commitment for distributed energy systems. Its name, latin for city, stems from its origin as a model for optimisation for urban energy systems. Since then, it has been adapted to multiple scales from neighbourhoods to continents.
 
-[![Documentation Status](https://readthedocs.org/projects/urbs/badge/?version=latest)](http://urbs.readthedocs.io/en/latest/?badge=latest)
+[![Documentation Status](https://urbs.readthedocs.io/en/extremos/)](https://urbs.readthedocs.io/en/extremos/)
 [![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.594200.svg)](https://doi.org/10.5281/zenodo.594200)
 
 ## eXtremOS project