add animation examples

Come up with examples where you can create animations.

Once there is a `wait` fn, an animation in Logo can created by drawing a picture, calling `wait`, calling `clean`, and doing it over again with another picture.

An animation using Logo functions will need to handle looping, termination, and loop state that each loop's picture can use. The easiest way is probably `(dotimes [i MAX-FRAMES] ...)`

Start by reviewing the existing Logo functions and the proposed animation flow using wait and clean. Define examples that cover looping, termination, and loop state, using dotimes and MAX-FRAMES as suggested. Done means the repository contains usable animation examples with those behaviors demonstrated.

Written by the indexing model from the issue text.