Add workflow intro

pages/Workflows.md

 Title: Workflow management
 Author: Jutta
 ---
+
+The simulation and raw data processing chains consist of workflows that are
+executed on heterogeneous clusters of computers. The harmonisation of workflow
+interfaces is one of the bigger challenges due to the large variety of software
+being used in individual processing steps. The benefits of a standardised
+interface lie in clarity and simplified maintainance. The Common Workflow
+Language (CWL) is currently being evaluated as an abstraction layer to describe
+analysis workflows and tools. It provides scalability and portability accross
+many different software and hardware environments.
+