Update Linux Introduction

Linux-Introduction.md

@@ -49,3 +49,11 @@ Most important info:
 - `/psi/home/$username:` 10GB , Backup 
 
 Data, Data Processing , Conda etc. should be in `/data/user/$username`, as it needs quite some storage, very important things that need to be backup-ed and are small go to `/psi/home/$username` 
+
+
+## Software 
+
+Software can be used in two ways: 
+1. load the available software via a [Pmodule](Pmodules)
+2. Install your software locally (in `/data/user/$username`)
+