Add material requirements

Author: gjbex

docs/README.md

@@ -65,6 +65,11 @@ from scratch.
 If you plan to do Python programming in a Linux or HPC environment you should
 be familiar with these as well.
 
+For following along hands-on, you need
+* laptop or desktop with internet access.
+* a Python environment that can run Jupyter Lab if you want to use your own system;
+* access to Google Colaboratory if you prefer not to install software.
+
 
 ## Level