Expand introduction.

README.md

 # The CADET-Research Data Management toolbox
 
+Welcome to CADET-RDM, a project by the Forschungszentrum Jülich.
+
+This tool aims to help track and version control:
+- input data
+- code
+- software versions
+- output data
+
+and allow for easy sharing, integration, and reproduction of generated results. 
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