Adding documentation.

README.md

@@ -25,3 +25,27 @@ TODO
 ### To Add Results
 
 TODO
+
+## Helpers
+
+### To extract a task
+
+First, clone the repo and install it locally with `pip install .` Then, make sure you have the desired task
+criteria and dataset predicates yaml files in their respective locations in the repo.
+
+Finally, run the following:
+
+```bash
+./src/MEDS_DEV/helpers/extract_task.sh $MEDS_ROOT_DIR $DATASET_NAME $TASK_NAME
+```
+
+E.g.,
+
+```bash
+./src/MEDS_DEV/helpers/extract_task.sh ../MEDS_TAB_COMPL_TEST/MIMIC-IV/ MIMIC-IV mortality/in_icu/first_24h
+```
+
+which will use the `datasets/MIMIC-IV/predicates.yaml` predicates file, the
+`tasks/criteria/mortality/in_icu/first_24h.yaml` task criteria, and will run over the dataset in the root
+directory at `../MEDS_TAB_COMPL_TEST/MIMIC-IV`, reading data from the `data` subdir of that root dir and
+writing labels to the `task_labels` subdir of that root dir, in a name dependent manner.