rename spacing to gap

src/core/trait_fns.rs

@@ -99,7 +99,7 @@ impl<const LEN: usize, Wa: WidgetArrLike<LEN, Tag>, Tag> CoreWidgetArr<LEN, Wa,
         move |ui| Span {
             children: self.ui(ui).arr.to_vec(),
             dir,
-            spacing: 0.0,
+            gap: 0.0,
         }
     }
     fn stack(self) -> StackBuilder<LEN, Wa, Tag> {