Syncthing Systemd Service & GTK on Startup

- Add systemd user service file to run syncthing daemon
- Add syncthing-gtk to list of startup applications

.scripts/startup.sh

@@ -31,6 +31,7 @@ declare -a delay_array=(\
     "/usr/bin/xfce4-power-manager" \         # XFCE4 Power Manager
     "/usr/bin/udiskie -a -n -s" \            # Udiskie
     "/usr/bin/openrgb" \                     # OpenRGB
+    "/usr/bin/syncthing-gtk" \               # Syncthing GTK
     # System Restore Processes
     "/usr/bin/autorandr --change --force" \  # Auto restore screen layout
     "/usr/bin/numlockx on" \                 # Enable numlock
@@ -46,6 +47,7 @@ declare -a kill_delay_array=(\
     "killall xfce4-power-manager" \   # XFCE4 Power Manager
     "killall udiskie" \               # Udiskie
     "killall openrgb" \               # OpenRGB
+    "killall syncthing-gtk" \         # Syncthing GTK
 )
 
 help_menu() {