Helper function to add caption-like annotations

[chriddyp]

No description provided.

[chriddyp]

function plotly_figure=add_caption(plotly_figure, caption)
    plotly_figure.layout.annotations{length(p.layout.annotations)+1} = struct(
        'text', 'test', 
        'xref', 'paper',
        'yref', 'paper',
        'xanchor', 'center',
        'yanchor', 'top',
        'x', 0.5, 'y', 0,
        'showarrow', false
    );

    plotly_figure.layout.margin.b = 1.5 * p.layout.margin.b;
end

[BRONSOLO]

addressed in: #59