add features to export app: let user select portrait vs landscape vs custom dim for PDF, allow user to have multiple plots per page, allow user to have plots arranged by row or by col, the plot preview is scaled according to the number of plots per page
add features to export app: let user select portrait vs landscape vs custom dim for PDF, allow user to have multiple plots per page, allow user to have plots arranged by row or by col, the plot preview is scaled according to the number of plots per page

smouksassi/ggplotwithyourdata,smouksassi/ggplotwithyourdata,smouksassi/ggplotwithyourdata