fix: adding image

docs/restore.md

@@ -2,6 +2,7 @@
 layout: article
 title: Data Restore
 description: How to restore a previous version of a Data Controller table
+og_image:  https://docs.datacontroller.io/img/restore.png
 ---
 
 # Data Restore
@@ -10,6 +11,8 @@ For those tables which have [Audit Tracking](/dcc-tables/#audit_libds) enabled,
 
 Simply open the submit to be reverted, and click the red REVERT button.  This will generate a NEW submission, containing the necessary reversal entries.  This new submission **must then be approved** in the usual fashion.
 
+![](/img/restore.png)
+
 Note that there are some caveats to this feature:
 
 - It will only work for TXTEMPORAL and UPDATE Load Types 
@@ -19,3 +22,8 @@ Note that there are some caveats to this feature:
 - If the model has changed (new / deleted columns) the restore will abort
 - Only submissions that have actually been loaded, can be reverted (obviously)
 
+## Technical Information
+
+The restore works by undoing all the changes listed in the [MPE_AUDIT](/tables/mpe_audit/) table.  The keys from this table (since and including the version to be restored) are left joined to the base table (to get current values) to create a staging dataset, and then the changes applied in reverse chronological order using [this macro](https://core.sasjs.io/mp__stripdiffs_8sas.html).
+
+Source code for the restore process is available here: https://git.datacontroller.io/dc/dc/src/branch/main/sas/sasjs/services/editors/restore.sas