Added a line about ProjectID to the Quick User Guide

README.md

@@ -24,6 +24,8 @@ Feel free to give feedback and feature requests or to take part in the developme
 
 `DataPaths.rdata =  {dataset1, dataset2};`  file names of the datasets (they most be at the path)
 
+You should either set a ProjectID in the config.json (copy & rename the 'example-config.json' to 'config.json'), or pass it as option 'ProjectID' to the TagPlot function.
+
 # PlotID.TagPlot()
 `[figs, IDs] = TagPlot(figs, options)`
 **TagPlot** adds IDs to figures