doc: Improve the security documentation

Author: siegfriedweber

docs/modules/opensearch/pages/usage-guide/security.adoc

@@ -37,7 +37,7 @@ When a new cluster is created, the security index is initialized from the follow
 * https://docs.opensearch.org/latest/security/configuration/yaml/#rolesyml[roles.yml{external-link-icon}^]:
   definition of roles in the security plugin
 * https://docs.opensearch.org/latest/security/configuration/yaml/#roles_mappingyml[roles_mapping.yml{external-link-icon}^]:
-  Role mappings to users or backend roles
+  role mappings to users or backend roles
 * https://docs.opensearch.org/latest/security/configuration/yaml/#tenantsyml[tenants.yml{external-link-icon}^]:
   OpenSearch Dashboards tenants
 
@@ -65,7 +65,7 @@ spec:
         tenants: ...
 ----
 
-If a setting is undefined, then a default configuration is deployed with no permissions.
+If any setting remains undefined, a default configuration will be deployed with no permissions.
 Therefore, it is okay to only define some settings and leave the others unspecified.
 
 A setting can be defined either inline, via Secret or ConfigMap:
@@ -129,7 +129,7 @@ spec:
 
 [WARNING]
 ====
-It is possible to change `managedBy` from `API` to `operator` after the cluster was created, but be aware that all changes made via the API are lost.
+While it is possible to change `managedBy` from `API` to `operator` after cluster creation, be cautious as this will discard all API-made changes.
 ====
 
 All settings managed by the operator are updated by the role group defined in `spec.clusterConfig.security.managingRoleGroup` which defaults to `security-config`:
@@ -180,10 +180,11 @@ Defaults to the `tls` SecretClass and can't be disabled.
 <3> The lifetime for autoTls certificates generated by the secret operator.
 Only a lifetime up to the `maxCertificateLifetime` setting in the SecretClass is applied.
 
-[WARNING]
+[IMPORTANT]
 ====
 The operator sets the configuration `plugins.security.nodes_dn` to `["CN=generated certificate for pod"]` which provides weak authentication between nodes.
-If you want to increase security and use certificates which identify the OpenSearch nodes specifically, you must also adapt the `plugins.security.nodes_dn` setting via configOverrides.
+For enhanced security, use certificates that uniquely identify the OpenSearch nodes.
+In this case, you must also adapt the `plugins.security.nodes_dn` setting via configOverrides.
 ====
 
 == Disabling security
@@ -203,11 +204,11 @@ spec:
       enabled: false
 ----
 
-All other security settings as well as the TLS settings are then ignored.
+Once disabled, all other security and TLS settings will be disregarded.
 
 [WARNING]
 ====
-If the security plugin was enabled before disabling it, then the security index is exposed to the public.
+If the security plugin was previously enabled, the security index will become accessible like any other indices.
 ====
 
-OpenSearch Dashboards require an enabled security plugin.
+OpenSearch Dashboards require the security plugin to be enabled.