split up the first paragraph of doc comments for better summaries

library/std/src/sync/mpmc/mod.rs

@@ -153,6 +153,7 @@ use crate::panic::{RefUnwindSafe, UnwindSafe};
 use crate::time::{Duration, Instant};
 
 /// Creates a new asynchronous channel, returning the sender/receiver halves.
+///
 /// All data sent on the [`Sender`] will become available on the [`Receiver`] in
 /// the same order as it was sent, and no [`send`] will block the calling thread
 /// (this channel has an "infinite buffer", unlike [`sync_channel`], which will
@@ -201,6 +202,7 @@ pub fn channel<T>() -> (Sender<T>, Receiver<T>) {
 }
 
 /// Creates a new synchronous, bounded channel.
+///
 /// All data sent on the [`Sender`] will become available on the [`Receiver`]
 /// in the same order as it was sent. Like asynchronous [`channel`]s, the
 /// [`Receiver`] will block until a message becomes available. `sync_channel`

library/std/src/sync/mpsc/mod.rs

@@ -483,6 +483,7 @@ pub enum TrySendError<T> {
 }
 
 /// Creates a new asynchronous channel, returning the sender/receiver halves.
+///
 /// All data sent on the [`Sender`] will become available on the [`Receiver`] in
 /// the same order as it was sent, and no [`send`] will block the calling thread
 /// (this channel has an "infinite buffer", unlike [`sync_channel`], which will
@@ -527,6 +528,7 @@ pub fn channel<T>() -> (Sender<T>, Receiver<T>) {
 }
 
 /// Creates a new synchronous, bounded channel.
+///
 /// All data sent on the [`SyncSender`] will become available on the [`Receiver`]
 /// in the same order as it was sent. Like asynchronous [`channel`]s, the
 /// [`Receiver`] will block until a message becomes available. `sync_channel`