Add example for runit service

etc/linux-runit/run

@@ -0,0 +1,8 @@
+#!/bin/sh
+
+export USERNAME=jb
+export HOME="/home/$USERNAME"
+export SYNCTHING="$HOME/bin/syncthing"
+
+setuidgid "$USERNAME" "$SYNCTHING" -logflags 0 2>&1 | logger -t syncthing
+