Update docs/guides/haiku_migration_guide.rst

Co-authored-by: 8bitmp3 <19637339+8bitmp3@users.noreply.github.com>

docs/guides/haiku_migration_guide.rst

@@ -791,7 +791,7 @@ we are telling ``nn.scan`` create different parameters for each step and slice t
  return y
 
 Notice how in Flax we pass ``None`` as the second argument to ``ScanBlock`` and ignore
-its second output, these represent the inputs/outputs per-step but they are ``None``
+its second output. These represent the inputs/outputs per-step but they are ``None``
 because in this case we don't have any.
 
 Initializing each model is the same as in previous examples. In this case,