Release fredr 2.0.0

[DavisVaughan]

Prepare for release:

• Check that description is informative
• Check licensing of included files
• devtools::build_readme()
• usethis::use_cran_comments()
• devtools::check(remote = TRUE, manual = TRUE)
• devtools::check_win_devel()
• rhub::check_for_cran()
• Update cran-comments.md
• Review pkgdown reference index for, e.g., missing topics

Submit to CRAN:

• usethis::use_version('major')
• devtools::submit_cran()
• Approve email

Wait for CRAN...

• Accepted 🎉
• usethis::use_github_release()
• usethis::use_dev_version()
• Tweet