summarize_sp_for_GD: Summarize number of species supporting gd
In Chien-Hsun/rePhylo: Re-investigating and Improving Phylogenies

Summarize the number of gd supported by each species, and the number of gd supported by how much species.

summarize_sp_for_GD(
  phyto,
  pdf = TRUE,
  pdfwid = NULL,
  pdflen = NULL,
  plot.type = "two"
)

`phyto`	a data.frame of gd table of a specific phyto node.
`pdf`	a logical specifying whether to export plots into pdf files. Defaults to `TRUE`.
`pdfwid`	a numeric for width of pdf file. Defaults to 5.
`pdflen`	optional. Length of pdf file. Defaults to `NULL`.
`plot.type`	characters to specify the type of plot. One of "two", "sp", "sp_num". Can be more than one.