Better release note and grammar

Author: seunghun1ee

etc/kayobe/ansible/deploy-radosgw-usage-exporter.yml

@@ -120,7 +120,7 @@
             ec2: "{{ credential.stdout | from_json | first }}"
           become: true
 
-        - name: Ensure the exporter to use certificate
+        - name: Ensure that the internal TLS certificate is trusted by the exporter
           when: stackhpc_radosgw_usage_exporter_cacert | length > 0
           block:
             - name: Create radosgw-usage-exporter directory

releasenotes/notes/add-radosgw-usage-exporter-support-93d55c544418b05a.yaml

@@ -5,3 +5,5 @@ features:
 
     To deploy the exporter, set the variable ``stackhpc_enable_radosgw_usage_exporter``
     to true. Then run playbook ``deploy-radosgw-usage-exporter.yml``.
+    A certificate path needs to be set to ``stackhpc_radosgw_usage_exporter_cacert``
+    if internal TLS is enabled.