precrec 0.16.2

A documentation release on GitHub only. CRAN still carries 0.14.5, and this
version is not being submitted there yet.

remotes::install_github("evalclass/precrec")

Changes in 0.16.2

• Rewrite the package website. The single long Introduction vignette is now
  a short Get started page plus three sets of short articles, reachable
  from new How-to, Measures and Plots menus: one page per task, one
  page per family of measures, and one page per plot. The vignette shipped
  with the package is the Get started page; the rest are on the website
  only, so nothing was added to the size of the package.

• Update README.md to match, and to describe the measures added in 0.15.0
  and 0.16.0.

• Shrink the logo. man/figures/logo.png was 3392 x 3392 pixels and 430 KB,
  and ships inside the package; it is now 240 x 240 and 13 KB, which is the
  size the README and the website actually display. The favicons are
  regenerated from it.