Fix relURL for custom_css (#252)
Fix relURL for custom_css (#252)

The way relURL was used meant that one needed to preface the custom_css
entries with a slash, or the href would be incorrectly set to
subdircss/mycss.css rather than subdir/css/mycss.css, in the case of
a baseURL in a subdir.

Co-authored-by: Nick White <46f1a0bd5592a2f9244ca321b129902a06b53e03@njw.name>
budparr/gohugo-theme-ananke,budparr/gohugo-theme-ananke