add window gaps

src/config/handler.rs

@@ -2440,6 +2440,7 @@ impl ConfigProxyHandler {
             BORDER_WIDTH => ThemeSized::border_width,
             BAR_HEIGHT => ThemeSized::bar_height,
             BAR_SEPARATOR_WIDTH => ThemeSized::bar_separator_width,
+            GAP => ThemeSized::gap,
             _ => return Err(CphError::UnknownSized(sized.0)),
         };
         Ok(sized)