Add package website and longer form documentation

[malcolmbarrett]

You should have a package website for documentation and the like, made with something like pkgdown or altdoc.

You can do this very quickly on GitHub with usethis::use_pkgdown_github_pages()

I would also like to see a vignette (usethis::use_vignette()) or article (usethis::use_article()) with the functionality of the package discussed, similar to the JOSS paper but made for new users or covering advanced topics

openjournals/joss-reviews#7319

[malcolmbarrett]

It looks like your vignette is not being picked up by pkgdown. You might need to add it to the yml file

https://pkgdown.r-lib.org/reference/build_articles.html#index-and-navbar