add window gaps

jay-config/src/theme.rs

@@ -363,5 +363,12 @@ pub mod sized {
         ///
         /// Default: 1
         const 04 => BAR_SEPARATOR_WIDTH,
+        /// The gap between tiled windows in pixels.
+        ///
+        /// When set to a value greater than 0, windows are separated by this
+        /// gap rather than by the border width.
+        ///
+        /// Default: 0
+        const 05 => GAP,
     }
 }