readme: improve spacing in label

Author: FabianHofmann

README.md

@@ -12,7 +12,7 @@
         **I**nteger\
         **N**on-linear\
         **O**ptimization in\
-        **P Y**thon
+        **PY**thon
 
 **linopy** is an open-source python package that facilitates **optimization** with **real world data**. It builds a bridge between data analysis packages like [xarray](https://github.com/pydata/xarray) & [pandas](https://pandas.pydata.org/) and problem solvers like [cbc](https://projects.coin-or.org/Cbc), [gurobi](https://www.gurobi.com/) (see the full list below). **Linopy** supports **Linear, Integer, Mixed-Integer and Quadratic Programming** while aiming to make linear programming in Python easy, highly-flexible and performant.