docs: generate example for server datasource (#790)

Author: h3adex

docs/data-sources/server.md

@@ -10,7 +10,14 @@ description: |-
 
 Server datasource schema. Must have a `region` specified in the provider configuration.
 
-
+## Example Usage
+
+```terraform
+data "stackit_server" "example" {
+  project_id = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
+  server_id  = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
+}
+```
 
 <!-- schema generated by tfplugindocs -->
 ## Schema