Add syncthing base, git submodules

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

users/nick/default.nix

@@ -18,6 +18,7 @@ in
     (import ../configs/bluetooth { inherit user; })
     (import ../configs/blueman { inherit user; })
     (import ../configs/cbatticon { inherit user; })
+    (import ../configs/syncthing { inherit user; })
     (import ../configs/brightnessctl { inherit user; })
     (import ../configs/pavucontrol { inherit user; })
     (import ../configs/pipewire { inherit user; })