Add 4.6.3 to 4.6.6 update steps (#2384)

Author: adriendupuis

docs/update_and_migration/from_4.5/update_from_4.5.md

@@ -451,3 +451,21 @@ ibexa:
                         channels:
                             - sms
 ```
+
+## v4.6.4
+
+#### Database update
+
+Run the following scripts:
+
+=== "MySQL"
+
+    ``` bash
+    mysql -u <username> -p <password> <database_name> < vendor/ibexa/installer/upgrade/db/mysql/ibexa-4.6.3-to-4.6.4.sql
+    ```
+
+=== "PostgreSQL"
+
+    ``` bash
+    psql <database_name> < vendor/ibexa/installer/upgrade/db/postgresql/ibexa-4.6.3-to-4.6.4.sql
+    ```