Update docs/toolhive/guides-cli/run-mcp-servers.mdx

Co-authored-by: Dan Barr <[email protected]>

Author: rdimitrov

docs/toolhive/guides-cli/run-mcp-servers.mdx

@@ -24,8 +24,9 @@ fetches website contents:
 thv run fetch
 ```
 
-If your custom registry includes groups, you can also run an entire group of
-servers:
+If you use a [custom registry](./registry.md#use-a-custom-registry) that
+includes groups, you can run multiple related servers together as a unit. This
+is useful when you need several servers for a specific workflow or project:
 
 ```bash
 thv group run <GROUP_NAME>