Update Johan's biography

Author: JohanMabille

src/components/about/Team/Johan.md

@@ -1,8 +1,10 @@
 
 Johan Mabille is a Technical Director specialized in high-performance computing in C++.
-He holds master's degree in computer science from Centrale-Supelec.
+He holds a master's degree in computer science from Centrale-Supelec.
 As an open source developer, Johan coauthored <a href="https://github.com/xtensor-stack/xtensor">xtensor</a> , <a href="https://github.com/jupyter-xeus/xeus">xeus</a> , and <a href="https://github.com/xtensor-stack/xsimd">xsimd</a>.
 
-He is also involved in the development of <a href="https://github.com/mamba-org/mamba">mamba</a>.
+He leads the C++ team at QuantStack, where he oversees the development and maintenance of <a href="https://github.com/mamba-org/mamba">mamba</a> and the <a href="https/github.com/jupyter-xeus">Jupyter Xeus</a> project.
 
-Prior to joining QuantStack, Johan was a quant developer at HSBC.
+Johan has also made significant contributions to <a href="https://github.com/jupyterlab/jupyterlab">JupyterLab</a>.
+
+Prior to joining QuantStack, Johan worked as a quant developer at HSBC.