fix links in vignette

vignettes/BuildingPredictiveModels.Rmd

@@ -1236,8 +1236,7 @@ The package has much more functionality than described in this vignette and cont
 | Custom Splitting Functions           | This vignette describes how you can add your own custom training/validation/testing splitting functions in the framework                                                                                                                                                     | [`Vignette`](https://github.com/OHDSI/PatientLevelPrediction/blob/main/inst/doc/AddingCustomSplitting.pdf)            |
 | Custom Sampling Functions            | This vignette describes how you can add your own custom sampling functions in the framework                                                                                                                                                                                  | [`Vignette`](https://github.com/OHDSI/PatientLevelPrediction/blob/main/inst/doc/AddingCustomSamples.pdf)              |
 | Custom Feature Engineering/Selection | This vignette describes how you can add your own custom feature engineering and selection functions in the framework                                                                                                                                                         | [`Vignette`](https://github.com/OHDSI/PatientLevelPrediction/blob/main/inst/doc/AddingCustomFeatureEngineering.pdf)   |
-| Ensemble models                      | This vignette describes how you can use the framework to build ensemble models, i.e combine multiple models in a super learner                                                                                                                                               | [`Vignette`](https://github.com/OHDSI/PatientLevelPrediction/blob/main/inst/doc/BuildingEnsembleModels.pdf)           |
-| Learning curves                      | Learning curves assess the effect of training set size on model performance by training a sequence of prediction models on successively larger subsets of the training set. A learning curve plot can also help in diagnosing a bias or variance problem as explained below. | [`Vignette`](https://github.com/OHDSI/PatientLevelPrediction/blob/main/inst/doc/GeneratingLearningCurves.pdf)         |
+| Learning curves                      | Learning curves assess the effect of training set size on model performance by training a sequence of prediction models on successively larger subsets of the training set. A learning curve plot can also help in diagnosing a bias or variance problem as explained below. | [`Vignette`](https://github.com/OHDSI/PatientLevelPrediction/blob/main/inst/doc/CreatingLearningCurves.pdf)         |
 
 # Demos