Suggestion related to the manuscript about serp

[ejikeugba]

Thanks for the helpful suggestions.

• The url with an error is fixed. I am not quite sure, but it seems the order of references in the paper can't be adjusted. They are lined up alphabetically by JOSS.
• Table 1 and Figure 1 are made more self-explanatory as suggested, with extra details added to the titles, also with some abbreviations replaced. vglm and serp are specifically referred to as R functions in the Table title.
• Line 64 is fine as suggested.
• The 'Statement of Need' and the 'State of the Field' previously in one section are now in separate sections.