Import HashMap visibly in the tutorial

docs/src/concepts/tasks.md

@@ -6,9 +6,8 @@ In `async-std`, the [`tasks`][tasks] module is responsible for this. The simples
 
 ```rust,edition2018
 # extern crate async_std;
-# use async_std::{fs::File, io::Read, task};
-# use std::io;
-#
+use async_std::{io, task, fs::File, io::Read};
+
 async fn read_file(path: &str) -> Result<String, io::Error> {
     let mut file = File::open(path).await?;
     let mut contents = String::new();

docs/src/tutorial/all_together.md

@@ -74,7 +74,7 @@ async fn client(mut broker: Sender<Event>, stream: TcpStream) -> Result<()> {
             Some(idx) => (&line[..idx], line[idx + 1 ..].trim()),
         };
         let dest: Vec<String> = dest.split(',').map(|name| name.trim().to_string()).collect();
-        let msg: String = msg.trim().to_string();
+        let msg: String = msg.to_string();
 
         broker.send(Event::Message { // 4
             from: name.clone(),

docs/src/tutorial/connecting_readers_and_writers.md

@@ -21,10 +21,7 @@ The order of events "Bob sends message to Alice" and "Alice joins" is determined
 # };
 # use futures::channel::mpsc;
 # use futures::SinkExt;
-# use std::{
-#     collections::hash_map::{Entry, HashMap},
-#     sync::Arc,
-# };
+# use std::sync::Arc;
 #
 # type Result<T> = std::result::Result<T, Box<dyn std::error::Error + Send + Sync>>;
 # type Sender<T> = mpsc::UnboundedSender<T>;
@@ -52,6 +49,8 @@ The order of events "Bob sends message to Alice" and "Alice joins" is determined
 #     })
 # }
 #
+use std::collections::hash_map::{Entry, HashMap};
+
 #[derive(Debug)]
 enum Event { // 1
     NewPeer {