Test file.
Different file name and title.
options(rmarkdown.html_vignette.check_title = FALSE)
to deal with below
Warning messages: 1: The vignette title specified in is different from the title in the YAML metadata. The former is “Flow and Salinity Data Sets”, and the latter is “Vignette, Create Seasonally Detrended Flow and Salinity Data Sets”. If that is intentional, you may set options(rmarkdown.html_vignette.check_title = FALSE) to suppress this check.