update changelog

Added information for:

    1. Retry and attempt to fix volume creations that encounter HTTP 422 errors
    2. Added support for Kubernetes 1.20
    3. Update sidecar versions.
    4. Fix for Operator’s OwnerReferences

CHANGELOG.md

@@ -9,17 +9,16 @@
 
 **Fixes:**
 - **Kubernetes:** Fixed issue where the Trident node failed to register with the Trident controller (Issue [#468](https://github.com/NetApp/trident/issues/468)).
+- **Kubernetes:** Fixed issue of Ownership References set by Trident Operator on cluster-scoped Trident resources
+ (Issue [#474](https://github.com/NetApp/trident/issues/474)).
 - Changed iSCSI static discovery to sendtargets
+- Fixed E-series intermittent HTTP 422 error on volume creation.
 
 **Enhancements:**
+- **Kubernetes:** Added support for Kubernetes 1.20
+- **Kubernetes:** Updated CSI sidecars.
 - Updated GCP driver to allow CVS-Performance volumes as small as 100 GiB.
 
-**Beta Features:**
-
-**Deprecations:**
-
-**Fixes:**
-
 ## v20.10.0
 
 - **IMPORTANT**: If you are upgrading from Trident 19.07 or 19.10 please carefully read [this](https://netapp-trident.readthedocs.io/en/stable-v20.07/kubernetes/upgrades/index.html).