Prepare pacakge for CRAN release

[Aeilert]

• Make sure there are no errors or warnings in R CMD check on local OS
• Make sure R CMD check also pass on other major OS and R versions, e.g using rhub or GHA
• Make sure all notes in R CMD check can be explained briefly. Preferably there should be 0 notes.
• Assign a version number (update DESCRIPTION and NEWS.md)
• Check all package URLs with {urlchecker}
• Confirm alignment with CRAN policies
• Confirm alignment with special considerations for first release (see below)
• Create a Github release for the accepted package version on CRAN

Special considerations for first release:

• usethis::use_news_md()
• usethis::use_cran_comments()
• Update (aspirational) install instructions in README
• Proofread Title: and Description:
• Check that all exported functions have @returns and @examples
• Check that Authors@R: includes a copyright holder (role ‘cph’)
• Check licensing of included files
• Review https://github.com/DavisVaughan/extrachecks