if we have a list of elements that we need to get a reference to, we can do that also.
as before, we're going to define a name, and use a css selector, but we'll use a different
function, one that gives us all the elements that match the selector.
when we have a list of things in javascript its called an array. arrays are really handy, but in order
to access a particular element in an array we need to use brackets and a number after its name. like
'myListOfElements[0]'. now for nerd reasons, in javascript the first element of an array is numbered 0
not one.