add missing newline in -h

rivet.sh

@@ -46,7 +46,7 @@ usage() {
 	printf "\t-s: Do not generate sitemap.xml\n"
 	printf "\t-u: Makes all references to the url 'http' instead of 'https'\n"
 	printf "\t-r: Do not generate an atom feed\n"
-	printf "\t-t: Do not insert contents of _metadata.html"
+	printf "\t-t: Do not insert contents of _metadata.html\n"
 	exit 2
 }