Update release notes for v0.11.0

Author: shantanualsi

changelogs/v0.11.0.md

@@ -9,6 +9,7 @@
 ## Removals
 
 This version removes support for chunk-tool following removal of chunk storage support in cortex.
+Benchtool is also not released as a part of this version. 
 
 ## Installation
 
@@ -23,17 +24,4 @@ $ chmod a+x "cortextool"
 
 # have fun :)
 $ ./cortextool --help
-```
-
-## benchtool
-
-```console
-# download the binary (adapt os and arch as needed)
-$ curl -fSL -o "benchtool" "https://github.com/grafana/cortex-tools/releases/download/v0.11.0/benchtool_0.11.0_linux_x86_64"
-
-# make it executable
-$ chmod a+x "benchtool"
-
-# have fun :)
-$ ./benchtool --help
-```
+```