make it easier to create this figure

[behinger]

Figure from @jschepers

coefs = coeftable(m)
coefnames = unique(coefs.coefname)

f = Figure(size = (1000, 400))
ga = f[1, 1] = GridLayout()
gb = f[1, 2] = GridLayout()

ax = Axis(
    ga[1, 1],
    title = "Estimated regression parameters",
    titlegap = 12,
    xlabel = "Time [s]",
    ylabel = "Amplitude [μV]",
    xlabelsize = 16,
    ylabelsize = 16,
    xgridvisible = false,
    ygridvisible = false,
)

for coef in coefnames
    estimate = filter(:coefname => ==(coef), coefs)
    lines!(ax, estimate.time, estimate.estimate, label = coef)
end
axislegend("Coefficient", framevisible = false)
hidespines!(ax, :t, :r)

f2 = plot_erp!(
    gb,
    effects(Dict(:condition => ["car", "face"], :continuous => -5:5), m);
    mapping = (; color = :continuous, linestyle = :condition, group = :continuous),
    legend = (; valign = :top, halign = :right, tellwidth = false),
    categorical_color = false,
    axis = (
        title = "Marginal effects",
        titlegap = 12,
        xlabel = "Time [s]",
        ylabel = "Amplitude [μV]",
        xlabelsize = 16,
        ylabelsize = 16,
        xgridvisible = false,
        ygridvisible = false,
    ),
    layout = (; showlegend = false),
);

# Workaround to separate legend and colorbar (will be fixed in a future UnfoldMakie version)
legend = f2.content[2].content
f2[:, 1] = legend

for (label, layout) in zip(["A", "B"], [ga, gb])
    Label(
        layout[1, 1, TopLeft()],
        label,
        fontsize = 26,
        font = :bold,
        padding = (0, 5, 5, 0),
        halign = :right,
    )
end

[vladdez]

fixed in #204