Remove the teaching of && in React Week 3

[kerimhudson]

Which module(s) and week(s) does this change affect? Module(s): React Week(s): 3

What is the work that needs to be done?

Use of the && for conditionals is considered bad practice, even if you don't have a second state. Rationale available from Kent Dodds: https://kentcdodds.com/blog/use-ternaries-rather-than-and-and-in-jsx

Why is this work important to do?

Helps iron out bad practises and potential issues in code early on.

Additional context

Who might need to know about this change?