Add a brief description of the print statement

We start using print later on, but it hasn't been explained.  This shows why you might want to use it instead of just letting the interpreter give you the repr of a variable.

Could go into more details on, eg, backslash-escaping of quotes, or print ('more\nthan\none\nline')...
I would prefer using `name = 'Ola'` rather than the traditional `hello world`.

I've found that it makes the participants subsitute their own name instead and they're more engaged as a result.