Add a primer for array vector operations

This primer walks through the new vector-like capabilities on 1D arrays.
Add Vass's suggestions to the array vector ops primer

Vass reviewed and made a few suggestions, so implemented them here.
Update arrayVectorOps.good

I forgot to update the .good after adding Vass's suggestions.
Merge pull request #445 from daviditen/vectorArrayPrimer

Add a primer for array vector operations

This primer walks through the new vector-like capabilities on 1D arrays.
[reviewed by Vass]