update python to 3.8 code example

Example 1: upgrade python to 3.8

$ sudo apt update -y
$ sudo apt install python3.8

Example 2: idle python download

# Python downloads IDLE on default when it's installed. 
# So you already should have it, but in case you don't, then:
# Reinstall python and make sure you tick the box that says "Install IDLE" or something like that