Change vline typ plot_model()

[EcoFlow]

@strengejacke I would highly appreciate if the plot_model function would not only offer a command to change the vline color but also provide a command to adjust the linetyp (dashed, dotted etc.)

While customizing a estimate plot I deeply missed something like a vline.type command

fe.effects <- plot_model(mod.sla, show.values = TRUE,
colors = "black", title = "",
vline.color = "red")

In my experience, most people want some sort of dotted line to indicate the zero line instead of a solid line. Maybe this is something worth implementing in the future. It would defenitely add to a already great and convenient package.