DOC improve example description for ingestion

Author: tomMoral

README.md

@@ -19,11 +19,11 @@ public and private test set.
     * `ingestion.py`: A script to run the ingestion. The role of this script is
       to load the submission code and produce predictions that can be evaluated
       with the `scoring_program`.
-      In our example, the submission define a `train_model` function that is
-      called with the training data, and returns a model from which we can call
-      the `predict` method.
-      The predictions are then stored as a csv file, to be loaded with the
-      `scoring_program`.
+      In our example, `the submission.py` define a `get_model` function that
+      returns a scikit-learn compatible model. This model is then fitted on the
+      training data calling `fit`, and the `predict` method is used to generate
+      predictions on the test data. These predictions are stored as a csv file,
+      to be loaded with the `scoring_program`.
 - `scoring_program/`: contains the scoring program that will be run to evaluate
   the predictions generated by the ingestion program. It loads the predictions
   and the ground truth labels, computes the evaluation metric (accuracy in this