Update documentation

Signed-off-by: Giuseppe Maxia <[email protected]>

website/docs/r/multisite_site_association.html.markdown

@@ -38,6 +38,9 @@ resource "vcd_multisite_site_association" "site1-site2" {
 ```
 Here, `var.remote_data` contains the same XML that was generated by `vcd_multisite_site_data` in the other site.
 Use this method if it is more convenient than reading XML from a file.
+The data could come from the field `associated_data` of a `vcd_multisite_site_data`, or from a `local_file.content`
+data source, or simply from a configuration file where it was collected by the current administrator.
+You can see an example of one such method in the folder `/examples/multi-site/site-all-at-once`.
 
 ## Argument Reference