Update es-connectors-sharepoint.md (#134004)

Explain what to do to ingest the root of the share point server.

docs/reference/search-connectors/es-connectors-sharepoint.md

@@ -147,6 +147,7 @@ The following configuration fields are required to set up the connector:
     * `collection1`
     * `collection1, collection2`
 
+To index from the root of all site collections, simply specify your SharePoint server URL in the `site_collections` field.
 
 `ssl_enabled`
 :   Whether SSL verification will be enabled. Default value is `False`.