Control over relative widths in `gseaplot2`

[Nelson-Gon]

Hi,

Awesome package. I was exploring some visualization with gseaplot2 and noticed that there is no direct control over relative plot widths.

  aplot::plot_list(gglist = plotlist, ncol = 1, heights = rel_heights)

Looking at the source of aplot::plot_list, it is unclear what the default relative widths are and perhaps this should be documented.

https://github.com/YuLab-SMU/aplot/blob/a5e824a1f84f54d16c6c1796a9bcfb95bd2b248c/R/plot-list.R#L32

 p <- Reduce(`+`, gglist, init = plot_filler()) + plot_layout(ncol = ncol, 
    nrow = nrow, byrow = byrow, widths = widths, heights = heights, 
    guides = guides, design = design)

Perhaps an argument rel_widths should be added to allow this customization in gseaplot2.

Thank you,

NelsonGon