Fix missing doc links

Found some places where links were not resolving correctly, this corrects them.

Author: alexrudy

tonic/src/transport/mod.rs

@@ -1,7 +1,7 @@
 //! Batteries included server and client.
 //!
 //! This module provides a set of batteries included, fully featured and
-//! fast set of HTTP/2 server and client's. These components each provide a or
+//! fast set of HTTP/2 server and client's. These components each provide a
 //! `rustls` tls backend when the respective feature flag is enabled, and
 //! provides builders to configure transport behavior.
 //!

tonic/src/transport/server/mod.rs

@@ -133,7 +133,7 @@ impl Default for Server<Identity> {
     }
 }
 
-/// A stack based `Service` router.
+/// A stack based [`Service`] router.
 #[derive(Debug)]
 pub struct Router<L = Identity> {
     server: Server<L>,