feat(router): Make Routes::prepare public

Author: tottoto

tonic/src/service/router.rs

@@ -83,11 +83,11 @@ impl Routes {
         self
     }
 
-    #[cfg(feature = "transport")]
-    pub(crate) fn prepare(self) -> Self {
+    /// This makes axum perform update some internals of the router that improves perf.
+    ///
+    /// See <https://docs.rs/axum/latest/axum/routing/struct.Router.html#a-note-about-performance>
+    pub fn prepare(self) -> Self {
         Self {
-            // this makes axum perform update some internals of the router that improves perf
-            // see https://docs.rs/axum/latest/axum/routing/struct.Router.html#a-note-about-performance
             router: self.router.with_state(()),
         }
     }