docs: update

Author: butterman0

pymc_extras/model_builder.py

@@ -638,6 +638,8 @@ def sample_posterior_predictive(self, X_pred, extend_idata, predictions, combine
             The input data used for prediction using prior distribution..
         extend_idata : Boolean determining whether the predictions should be added to inference data object.
             Defaults to False.
+        predictions : Boolean determing whether to use the predictions group for posterior predictive sampling.
+            Defaults to True.
         combined: Combine chain and draw dims into sample. Won't work if a dim named sample already exists.
             Defaults to True.
         **kwargs: Additional arguments to pass to pymc.sample_posterior_predictive