hint to use Singularity container to run scripts in the repository

README.md

@@ -11,3 +11,7 @@ You need an OpenStructure and ProMod3 installation to run the scripts,
 more specifically you need the *ost* and *pm* executables in your path.
 Furthermore you need the numpy, scipy and matplotlib Python modules. 
 
+You may want to try a ProMod3 Singularity container
+(https://openstructure.org/promod3/3.1/container/singularity) which should
+contain the software required to execute most of the scripts in this repository.
+