Importing logShow

[prescientmoon]

So a friend of mine started reading trough the book, and when he got to the getting-started section - which told him to use the logShow function - he was really confused because he got an error (caused by the fact logShow wasn't imported).

So that section already explains importing Math and Prelude so I think we should add another note on importing the logShow function.

[milesfrain]

In the previous section, it instructs users to start with this:

module Main where

import Effect.Console

main = log "Hello, World!"

But I agree that this is not the most straightforward presentation. I'd like to overhaul this chapter as described in #93.

[milesfrain]

#144 should improve this getting-started experience.