Remove changes that not affect the provisioner from the changelog

CHANGELOG.md

 # v4.0.0
 - Remove redundant field in the rbac.yaml (https://github.com/kubernetes-retired/external-storage/pull/970)
-- Fixing documentation to be correct for both `kubectl` and `oc` (https://github.com/kubernetes-retired/external-storage/pull/969)
-- Point users to Helm and split up yamls (https://github.com/kubernetes-retired/external-storage/pull/995)
 - Use `kubernetes-sigs/sig-storage-lib-external-provisioner` instaed of `incubator/external-storage/lib` (https://github.com/kubernetes-retired/external-storage/pull/1026)
 - Fill in rbac.yaml with ServiceAccount manifest (https://github.com/kubernetes-retired/external-storage/pull/1060, https://github.com/kubernetes-retired/external-storage/pull/1179)
-- Fix some typos in README (https://github.com/kubernetes-retired/external-storage/pull/1054)
 - Make ARM deployment consistent with regular deployment (https://github.com/kubernetes-retired/external-storage/pull/1090)
 - Update Deployment apiVersion (from `extensions/v1beta1` to `apps/v1`) and added selector field (https://github.com/kubernetes-retired/external-storage/pull/1230/, https://github.com/kubernetes-retired/external-storage/pull/1231/, https://github.com/kubernetes-retired/external-storage/pull/1283/, https://github.com/kubernetes-retired/external-storage/pull/1294/)
 - Fix namespace in deployments (https://github.com/kubernetes-retired/external-storage/pull/1087, https://github.com/kubernetes-retired/external-storage/pull/1279)
@@ -15,7 +12,6 @@
 - Enable mountOptions from StorageClass to PersistentVolume (https://github.com/kubernetes-sigs/nfs-subdir-external-provisioner/pull/28)
 
 # v3.1.0
-- README Clarifications and minor formatting improvements (https://github.com/kubernetes-retired/external-storage/pull/938/)
 - Make leader-election configurable: default endpoints object namespace to controller's instead of kube-system (https://github.com/kubernetes-retired/external-storage/pull/957)
 
 # v3.0.1
@@ -37,7 +33,6 @@
 - Fix Makefile to build on OSX (https://github.com/kubernetes-retired/external-storage/pull/661)
 - Change the RBAC apiVersion from `rbac.authorization.k8s.io/v1alpha1` to `rbac.authorization.k8s.io/v1` (https://github.com/kubernetes-retired/external-storage/pull/656)
 - Add serviceAccount to deployment (https://github.com/kubernetes-retired/external-storage/pull/653)
-- README Improvements (https://github.com/kubernetes-retired/external-storage/pull/687)
 - Add namespace extended attributes to directory (https://github.com/kubernetes-retired/external-storage/pull/672)
 
 # v2.0.1