This is a convenience function to facilitate reading logfiles. It opens
a HTML browser using utils::browseURL(). It will search for
the environment variable "GRETA_INSTALLATION_LOG" or default to
tools::R_user_dir("greta"). To set
"GRETA_INSTALLATION_LOG" you can use
Sys.setenv('GRETA_INSTALLATION_LOG'='path/to/logfile.html'). Or use
greta_set_install_logfile() to set the path, e.g.,
greta_set_install_logfile('path/to/logfile.html').