Clarify that the cortex bucket is intended for the cluster's use only

Author: deliahu

docs/cluster-management/config.md

@@ -23,9 +23,10 @@ cluster_name: cortex
 region: us-west-2
 
 # S3 bucket (default: <cluster_name>-<RANDOM_ID>)
+# note: your cortex cluster uses this bucket for metadata storage, and it should not be accessed directly (a separate bucket should be used for your models)
 bucket: # cortex-<RANDOM_ID>
 
-# List of availability zones for your region (default: 3 random availability zones from the specified region)
+# list of availability zones for your region (default: 3 random availability zones from the specified region)
 availability_zones: # e.g. [us-west-2a, us-west-2b, us-west-2c]
 
 # instance type

docs/cluster-management/uninstall.md

@@ -24,6 +24,10 @@ If you modified your bash profile, you may wish to remove `source <(cortex compl
 
 ## Cleaning up AWS
 
+Since you may wish to have access to your data after spinning down your cluster, Cortex's bucket and log groups are not automatically deleted when running `cortex cluster down`.
+
+To delete them:
+
 ```bash
 # set AWS credentials
 export AWS_ACCESS_KEY_ID=***