Takes a data frame object and makes it into a pretty table. This is designed
to work within the adlgraphs package but it should work with most objects
of class tbl_df, tbl, or data.frame. Very important note, at the moment,
this only works with frequency tables that have columns labelled pct and
n. I do not see this changing for frequency tables. Nevertheless, I am
working on adding in more functionality, including for mean tables, tables of
factor loadings, linear regression coefficients, and others.