JS 4: Task 2 BBC api no longer available

[kyorkston]

The note
**Part 2 of this exercise is no longer possible as the API that it uses has been taken down by the BBC.** **Sorry, we're working on fixing the exercise!**
has been in the Readme for a while, the exercise needs replaced because APIs are fun!

I have created a PR to add a different exercise using a quiz API

#453