Only copy the CSS if it does not exist.

run.sh

@@ -6,6 +6,8 @@ cd $DIR
 rm -rfv public
 mkdir -pv public
 
-cp -rv themes/lugo/static/style.css static/
+if [[ ! -f static/style.css ]]; then
+	cp -rv themes/lugo/static/style.css static/
+fi
 
 hugo server -D --noBuildLock