SUMO-258848: updates documentation for partition resource

Author: raghavxk

website/docs/r/partition.html.markdown

@@ -29,6 +29,7 @@ The following arguments are supported:
 - `name` - (Required, Forces new resource) The name of the partition.
 - `routing_expression` - (Required) The query that defines the data to be included in the partition.
 - `analytics_tier` - (Optional) The cloud flex analytics tier for your data; only relevant if your account has basic analytics enabled. If no value is supplied, partition will be created in continuous tier. Other possible values are : "frequent" and "infrequent". For flex partition, you can leave it empty or send flex.
+This field is set during partition creation and cannot be modified later by the user. However, Terraform can detect and reconcile backend-driven changes, such as those resulting from a Flex migration.
 - `retention_period` - (Optional) The number of days to retain data in the partition, or -1 to use the default value for your account. Only relevant if your account has variable retention enabled.
 - `is_compliant` - (Optional) Whether the partition is compliant or not. Mark a partition as compliant if it contains data used for compliance or audit purpose. Retention for a compliant partition can only be increased and cannot be reduced after the partition is marked compliant. A partition once marked compliant, cannot be marked non-compliant later.
 - `reduce_retention_period_immediately` - (Optional) This is required on update if the newly specified retention period is less than the existing retention period. In such a situation, a value of true says that data between the existing retention period and the new retention period should be deleted immediately; if false, such data will be deleted after seven days. This property is optional and ignored if the specified retentionPeriod is greater than or equal to the current retention period.