title: How do you increase the size of lists inside a list
body: <p>I'm trying to figure out how to increase the size of the lists inside a list of lists. For example <code>[[1,2,3,4], [1,2,3,4],[1,2,3,4]]</code> and want to be able to add 1 more onto it so it is <code>[[1,2,3,4,5], [1,2,3,4,5],[1,2,3,4,5]]</code>. The numbers are just to show i want them to now have a new element in each.</p>