Some notes in Docco.

index.js

@@ -67,6 +67,8 @@ function cadence () {
     callback.errors = [];
     callback.catchers = [];
     callback.steps = [];
+    // TODO: DOCUMENT: Only one finalizer after each step. You cannot have two
+    // consecutive finalizers.
     callback.finalizers = [];
     // TODO: No good way to prevent or preserve callbacks. Step function needs
     // to be in array.
@@ -351,6 +353,9 @@ function cadence () {
 
     args = previous.__args;
 
+    // Add the finalizers for the current step. Save the previous invocation
+    // with the step so we can invoke the finalizer with arguments generated by
+    // the previous invocation.
     if (cadence.finalizers[index]) {
       previous.finalizers.push(cadence.finalizers[index]);
       cadence.finalizers[index].previous = previous;