add more comments around region ids (#34)

temporal/api/cloud/cloudservice/v1/request_response.proto

@@ -236,6 +236,8 @@ message AddNamespaceRegionRequest {
     // The namespace to add the region to.
     string namespace = 1;
     // The id of the standby region to add to the namespace.
+    // The GetRegions API can be used to get the list of valid region ids.
+    // Example: "aws-us-west-2".
     string region = 2;
     // The version of the namespace for which this add region operation is intended for.
     // The latest version can be found in the GetNamespace operation response.

temporal/api/cloud/namespace/v1/message.proto

@@ -63,11 +63,13 @@ message NamespaceSpec {
     // The name is immutable. Once set, it cannot be changed.
     string name = 1;
     // The ids of the regions where the namespace should be available.
+    // The GetRegions API can be used to get the list of valid region ids.
     // Specifying more than one region makes the namespace "global", which is currently a preview only feature with restricted access.
     // Please reach out to Temporal support for more information on global namespaces.
     // When provisioned the global namespace will be active on the first region in the list and passive on the rest.
     // Number of supported regions is 2.
     // The regions is immutable. Once set, it cannot be changed.
+    // Example: ["aws-us-west-2"].
     repeated string regions = 2;
     // The number of days the workflows data will be retained for.
     // Changes to the retention period may impact your storage costs.