bug: validate_age_group can now be imported
enh: add show() to all graphics files
bug: win v cluster load data
rename applications to graphics for all pdfs
graphics folder added
enh: all graphics in book/graphics folder
enh: suppressed output and graphics folder
enh: all graphics
bug: graphics filepath tex change
enh: set_font func
bug: graphics file
BOOK: review edits
BOOK: missing references