Update README.md

Author: haykh

README.md

@@ -13,7 +13,7 @@ One particle-in-cell code to rule them all. Find our detailed documentation [her
 
 🥔 __Jens Mahlmann__ {[@jmahlmann](https://github.com/jmahlmann): framework, MPI}
 
-🐬__Sasha Philippov__ {[@sashaph](https://github.com/sashaph): all-around}
+🐬 __Sasha Philippov__ {[@sashaph](https://github.com/sashaph): all-around}
 
 🤷 __Arno Vanthieghem__ {[@vanthieg](https://github.com/vanthieg): PIC}