Stored/Transformed/Created column in the table descriptions

[tompollard]

@obadawi In each page that describes the eICU tables, there is a column titled "Stored Transformed Created" in the "Table descriptions" section (e.g. see: https://eicu-crd.mit.edu/eicutables/admissiondrug/).

Is this column important to include in the documentation? If so, please could you explain what it means? If you don't think the column is important, then I'll remove it from the pages where it appears.