Fix a few typos in docs and comments (#2808)

examples/consume-body-in-extractor-or-middleware/src/main.rs

@@ -50,7 +50,7 @@ async fn print_request_body(request: Request, next: Next) -> Result<impl IntoRes
 async fn buffer_request_body(request: Request) -> Result<Request, Response> {
     let (parts, body) = request.into_parts();
 
-    // this wont work if the body is an long running stream
+    // this won't work if the body is an long running stream
     let bytes = body
         .collect()
         .await

examples/rest-grpc-multiplex/src/multiplex_service.rs

@@ -38,7 +38,7 @@ where
         Self {
             rest: self.rest.clone(),
             grpc: self.grpc.clone(),
-            // the cloned services probably wont be ready
+            // the cloned services probably won't be ready
             rest_ready: false,
             grpc_ready: false,
         }