Apply suggestion from @Copilot

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: Tuntii

docs/cookbook/src/crates/rustapi_extras.md

@@ -18,6 +18,7 @@ This crate is a collection of production-ready middleware. Everything is behind
 | `replay` | `ReplayLayer` (Time-Travel Debugging) |
 | `timeout` | `TimeoutLayer` |
 | `guard` | `PermissionGuard` |
+| `sanitization` | Input sanitization utilities |
 
 ## Middleware Usage