docs: Fix duplicate words in README (#734)

tower/README.md

@@ -44,7 +44,7 @@ middleware with [`Service`]s. If a [`Service`] can be thought of as an
 asynchronous function from a request type to a response type, a [`Layer`] is
 a function taking a [`Service`] of one type and returning a [`Service`] of a
 different type. The [`ServiceBuilder`] type is used to add middleware to a
-service by composing it with multiple multiple [`Layer`]s.
+service by composing it with multiple [`Layer`]s.
 
 ### The Tower Ecosystem
 
@@ -95,7 +95,7 @@ Depending on your particular use case, you might use Tower in several ways:
 
   Additionally, when a network protocol requires functionality already
   provided by existing Tower middleware, a protocol implementation might use
-  Tower middleware internally, as well as as an integration point.
+  Tower middleware internally, as well as an integration point.
 
 ### Library Support