fix some typos

Signed-off-by: cuishuang <imcusg@gmail.com>

Author: cuishuang

CHANGELOG.md

@@ -155,7 +155,7 @@ release, and updates internal dependencies.
 ## Fixed
 
 - Fix `TcpListener::incoming`. ([#889](https://github.com/async-rs/async-std/pull/889))
-- Fix tokio compatability flag. ([#882](https://github.com/async-rs/async-std/pull/882))
+- Fix tokio compatibility flag. ([#882](https://github.com/async-rs/async-std/pull/882))
 
 # [1.6.4] - 2020-09-16
 
@@ -207,7 +207,7 @@ release, and updates internal dependencies.
 
 ## Added
 
-- Added `tokio02` feature flag, to allow compatability usage with tokio@0.2 ([#804](https://github.com/async-rs/async-std/pull/804)).
+- Added `tokio02` feature flag, to allow compatibility usage with tokio@0.2 ([#804](https://github.com/async-rs/async-std/pull/804)).
 
 ## Changed
 

src/future/mod.rs

@@ -2,7 +2,7 @@
 //!
 //! ## Base Futures Concurrency
 //!
-//! Often it's desireable to await multiple futures as if it was a single
+//! Often it's desirable to await multiple futures as if it was a single
 //! future. The `join` family of operations converts multiple futures into a
 //! single future that returns all of their outputs. The `race` family of
 //! operations converts multiple future into a single future that returns the

src/stream/stream/cmp.rs

@@ -58,7 +58,7 @@ where
                 return Poll::Ready(Ordering::Greater);
             }
 
-            // Get next value if possible and necesary
+            // Get next value if possible and necessary
             if !this.l.done && this.l_cache.is_none() {
                 let l_next = futures_core::ready!(this.l.as_mut().poll_next(cx));
                 if let Some(item) = l_next {

src/stream/stream/partial_cmp.rs

@@ -59,7 +59,7 @@ where
                 return Poll::Ready(Some(Ordering::Greater));
             }
 
-            // Get next value if possible and necesary
+            // Get next value if possible and necessary
             if !this.l.done && this.l_cache.is_none() {
                 let l_next = futures_core::ready!(this.l.as_mut().poll_next(cx));
                 if let Some(item) = l_next {