docs: Fix some spelling mistakes (#747)

tower/src/retry/backoff.rs

@@ -1,4 +1,4 @@
-//! This module contains generic [backoff] utlities to be used with the retry
+//! This module contains generic [backoff] utilities to be used with the retry
 //! layer.
 //!
 //! The [`Backoff`] trait is a generic way to represent backoffs that can use

tower/src/retry/budget/tps_budget.rs

@@ -31,7 +31,7 @@ pub struct TpsBudget {
     slots: Box<[AtomicIsize]>,
     /// The amount of time represented by each slot.
     window: Duration,
-    /// The changers for the current slot to be commited
+    /// The changers for the current slot to be committed
     /// after the slot expires.
     writer: AtomicIsize,
     /// Amount of tokens to deposit for each put().

tower/src/util/rng.rs

@@ -3,7 +3,7 @@
 //! This module provides a generic [`Rng`] trait and a [`HasherRng`] that
 //! implements the trait based on [`RandomState`] or any other [`Hasher`].
 //!
-//! These utlities replace tower's internal usage of `rand` with these smaller,
+//! These utilities replace tower's internal usage of `rand` with these smaller,
 //! more lightweight methods. Most of the implementations are extracted from
 //! their corresponding `rand` implementations.
 //!
@@ -111,7 +111,7 @@ where
 
 /// A sampler modified from the Rand implementation for use internally for the balance middleware.
 ///
-/// It's an implemenetation of Floyd's combination algorithm. with amount fixed at 2. This uses no allocated
+/// It's an implementation of Floyd's combination algorithm. with amount fixed at 2. This uses no allocated
 /// memory and finishes in constant time (only 2 random calls)
 ///
 /// ref: This was borrowed and modified from the following Rand implementation

tower/tests/ready_cache/main.rs

@@ -200,7 +200,7 @@ async fn cancelation_observed() {
     let mut handles = vec![];
 
     // NOTE This test passes at 129 items, but fails at 130 items (if coop
-    // schedulding interferes with cancelation).
+    // scheduling interferes with cancelation).
     for _ in 0..130 {
         let (svc, mut handle) = tower_test::mock::pair::<(), ()>();
         handle.allow(1);