Add TOC and Changelog entries for recent features

Author: kilokahn

CHANGELOG.md

@@ -12,6 +12,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/).
 - Fix to example in Route Tables documentation file.
 - Added support for AuthToken Resource (replacement of deprecated SwiftPasswords) in Identity Service.
 - Added support for Volume Group and Volume Group Backup.
+- HCL syntax highlighting in docs
+- Nil checks for time properties to avoid panic
 
 ## 2.1.10 - 2018-05-24
 

docs/Table of Contents.md

@@ -32,6 +32,8 @@ This lists all of the available OCI resources and/or data sources.
     * [Volume Attachments](https://github.com/oracle/terraform-provider-oci/tree/master/docs/core/volume_attachments.md)
     * [Volume Backups](https://github.com/oracle/terraform-provider-oci/tree/master/docs/core/volume_backups.md)
     * [Volumes](https://github.com/oracle/terraform-provider-oci/tree/master/docs/core/volumes.md)
+    * [VolumeGroups](https://github.com/oracle/terraform-provider-oci/tree/master/docs/core/volume_groups.md)
+    * [VolumeGroupBackups](https://github.com/oracle/terraform-provider-oci/tree/master/docs/core/volume_group_backups.md)
 * **Database**
     * [Databases](https://github.com/oracle/terraform-provider-oci/tree/master/docs/database/databases.md)
     * [DB Homes](https://github.com/oracle/terraform-provider-oci/tree/master/docs/database/db_homes.md)