Doc fix for VCN cidr_block

Author: zexinwanoci

website/docs/r/core_vcn.html.markdown

@@ -75,13 +75,13 @@ resource "oci_core_vcn" "test_vcn" {
 The following arguments are supported:
 
 * `cidr_block` - (Optional) **Deprecated.** Do *not* set this value. Use `cidrBlocks` instead. Example: `10.0.0.0/16` 
-* `cidr_blocks` - (Optional) The list of one or more IPv4 CIDR blocks for the VCN that meet the following criteria:
+* `cidr_blocks` - (Optional) (Updatable) The list of one or more IPv4 CIDR blocks for the VCN that meet the following criteria:
 	* The CIDR blocks must be valid.
 	* They must not overlap with each other or with the on-premises network CIDR block. 
 	* The number of CIDR blocks must not exceed the limit of CIDR blocks allowed per VCN.
         a. The list of CIDRs provided are valid 
         b. There is no overlap between different CIDRs 
-        c. The number of CIDRs should not exceed the max limit of CIDRs per VCN d. It is an error to set both cidrBlock and cidrBlocks. Note: cidr_blocks update must be restricted to one operation at a time (either add/remove or modify one single cidr_block) or the operation will be declined. new cidr_block to be added must be placed at the end of the list
+        c. The number of CIDRs should not exceed the max limit of CIDRs per VCN d. It is an error to set both cidrBlock and cidrBlocks. Note: cidr_blocks update must be restricted to one operation at a time (either add/remove or modify one single cidr_block) or the operation will be declined. new cidr_block to be added must be placed at the end of the list. Once you migrate to using `cidr_blocks` from `cidr_block`, you will not be able to switch back.
 	**Important:** Do *not* specify a value for `cidrBlock`. Use this parameter instead. 
 * `compartment_id` - (Required) (Updatable) The OCID of the compartment to contain the VCN.
 * `defined_tags` - (Optional) (Updatable) Defined tags for this resource. Each key is predefined and scoped to a namespace. For more information, see [Resource Tags](https://docs.cloud.oracle.com/iaas/Content/General/Concepts/resourcetags.htm).  Example: `{"Operations.CostCenter": "42"}`