merge works well. added a preliminary check_varnames to check for what varnames are found in your particular data
major change in merging the data files. Instead of custom id-variable, now the merge is done using RB010, RB020, RB030 etc. vars as they are. In the output only the ids from first dataset are preserved.
instead of replacing the file names of original .csv's, now you have to specify the path for each csv. Update will break the old code
updating the vignette file