Add coverage to plot_score_table()

[nikosbosse]

Currently there is no way to have coverage displayed on the plot_score_table() plot. The following code will just remove it:

example_quantile %>%
    score() %>%
    add_coverage(by = c("model")) %>%
    summarise_scores(by = c("model")) %>%
    summarise_scores(by = c("model"), fun = signif, digits = 1) %>%
    plot_score_table()

Would be nice to add it