(step-02) Add missing ViewerQueries headstart code

[thomastuts]

The docs mention the following in the 'Exercise 2' section:

To give you a headstart, we already defined ViewerQueries in index.js.

However, this bit of code is not in the step-02 branch. This PR fixes that!

[marktani]

hm I think we had an almost identical PR some time ago. Will further investigate!

[marktani]

See #12

The thing is that we either have a esllint error or a missing line of code 😛
Do you mind to instead change the text itself over at https://github.com/learnrelay/learnrelay/blob/master/content/queries/containers-fragments.md#composing-queries-using-fragments and https://github.com/learnrelay/learnrelay/blob/master/content/queries/containers-fragments.md#exercise-02-prepare-the-listpage-for-further-action to instruct the user to copy the line of code in the exercise themselves?

[marktani]

I need to have a look at the ViewerQueries issues and come up with a consistend solution