Typo fix in inc/pandoc_wrapper.sh

inc/pandoc_wrapper.sh

@@ -63,7 +63,7 @@ export USAGE="usage: $0 [-h] [-v level] [-V] [-n] [-N]
 	file.md		markdown file to convert into HTML
 	output.html	HTML generated by pandoc from file.md
 			NOTE: Without -n, will prepend -o output.html as first pandoc options
-			      With -n, will append -o /dv/null as last pandoc options before file.md
+			      With -n, will append -o /dev/null as last pandoc options before file.md
 
 Exit codes:
      0         all OK