Update README.md

Fix the version on the spglib installation guide

Author: mesonepigreco

README.md

@@ -12,7 +12,7 @@ The SSCHA code comes as a python library, with computationally intense part spee
 
 
 ```
-conda create -n sscha -c conda-forge python=3.10 gfortran libblas lapack openmpi julia openmpi-mpicc pip numpy scipy spglib
+conda create -n sscha -c conda-forge python=3.10 gfortran libblas lapack openmpi julia openmpi-mpicc pip numpy scipy spglib=2.2
 conda activate sscha
 pip install ase julia mpi4py
 pip install cellconstructor python-sscha tdscha