adapted to template for Problem 2.1

docs/exercise2.rst

@@ -2,17 +2,30 @@ Exercise 2: Managing data flow
 ==============================
 
 The purpose of this exercise is to learn how to pass data between fireworks and 
-describe data dependencies using the custom firetask ``PythonFunctionTask``.
+describe data dependencies using the custom firetask ``PythonFunctionTask``::
+
+    - _fw_name: PythonFunctionTask
+      function: any_module.any_function
+      inputs:
+      - first argument
+      - second argument
+      outputs:
+      - data to forward
+
+The keys specified in the ``inputs`` list must be available in the firework 
+``spec`` at task run time. These are passed as positional arguments to the 
+function. The returned outputs will be stored in the specs of the current firework 
+and of the child fireworks under the keys specified in the ``outputs`` list.
 
 
 Problem 2.1
 -----------
 
 Change to folder **exercises/work/2_data_flow**. Copy the provided template 
-**exercises/inputs/2_data_flow/template.json** and complete it so that the script
-**exercises/problems/recruiting-script.py** is implemented as a workflow. Check
-the workflow, add it to LaunchPad and run it in singleshot mode watching the 
-changes in the fireworks with the workflow run. 
+**exercises/inputs/2_data_flow/template.[json|yaml]** and complete it so that 
+the script **exercises/problems/recruiting-script.py** is implemented as a 
+workflow. Check the workflow, add it to LaunchPad and run it in singleshot mode 
+watching the changes in the fireworks with the workflow run. 
 
 
 Problem 2.2