TiagoOlivoto/metan: v1.8.1

Use \doi{} markup in Rd files. New function gytb() to generate the Genotype by yield*trait biplot. New functions row_col_mean() and row_col_sum()to add a row with the mean/sum of each variable and a column with the the mean/sum for each row of a matrix or data frame. New functions has_zero(), remove_cols_zero(), remove_rows_zero(), select_cols_zero(), select_rows_zero(), and replace_zero() to deal with 0s in a data frame. Fix bug of inconsistent color legend when plotting objects of class gge. Include class gge and can_corr in get_model_data(). New argument position in plot.gamem() and plot.mtsi() to control the position adjustment of the bar plot. New argument col.by in corr_plot() to map the color of the points by a categorical variable. New argument use_data in functions mgidi(), fai_blup(), and Smith_Hazel() to control which data is used (BLUPs or phenotypic means) to compute the index. inspect() now generate a warning if zero values are observed in data