Hide fewer-braces page.

See b1a6867.

Author: julienrf

project/resources/referenceReplacements/sidebar.yml

@@ -135,6 +135,7 @@ subsection:
     index: reference/experimental/overview.md
     subsection:
       - page: reference/experimental/fewer-braces.md
+        hidden: true
       - page: reference/experimental/canthrow.md
       - page: reference/experimental/erased-defs.md
       - page: reference/experimental/erased-defs-spec.md