Added pointers to the colorspace package and base R in a new
startup message. The colorspace package provides better functions
for simulating color vision deficiency: simulate_cvd(), deutan(),
protan(), tritan(). More modern robust color palettes are available
in hcl.colors() and palette.colors() in base R as well as further
tools in colorspace. References providing more details:
https://doi.org/10.18637/jss.v096.i01 and
https://doi.org/10.32614/RJ-2023-071.
Code repository changed from R-Forge to Codeberg at: https://codeberg.org/zeileis/dichromat/
Added basic altdoc page with overview and documentation at: https://zeileis.codeberg.page/dichromat/
Achim Zeileis takes over maintenance.