docs: Finish describing memoization

Complete my sentence from PR argoproj#11257

Signed-off-by: Alan Clucas <[email protected]>

docs/work-avoidance.md

@@ -4,7 +4,7 @@
 
 You can make workflows faster and more robust by employing **work avoidance**. A workflow that utilizes this is simply a workflow containing steps that do not run if the work has already been done.
 
-This technique is similar to [memoization](memoization.md) but they have distinct use cases. Work avoidance is totally in your control and you make the decisions as to have to skip the work. [Memoization](memoization.md) is a feature of Argo Workflows to automatically skip steps which generate outputs - it is designed
+This technique is similar to [memoization](memoization.md) but they have distinct use cases. Work avoidance is totally in your control and you make the decisions as to have to skip the work. [Memoization](memoization.md) is a feature of Argo Workflows to automatically skip steps which generate outputs - it is designed for pure steps which only generate output based on their inputs.
 
 This simplest way to do this is to use **marker files**.