How to append a list to an existing list of lists? : <p>If I have a list of lists <code>[[1,1,1,1],[2,2,2,2]]</code> how do I add a 3rd list <code>[3,3,3,3]</code> to it to make it <code>[[1,1,1,1],[2,2,2,2],[3,3,3,3]]</code></p>
