Fix link to OSISM testbed docs.

Signed-off-by: Kurt Garloff <[email protected]>

Author: garloff

docs/index.mdx

@@ -40,7 +40,7 @@ virtualization.
 
 Read the [testbed docs](/docs/iaas/deployment-examples/testbed) to learn how to get the
 testbed running. Please read carefully through the
-[deployment](https://docs.osism.de/testbed/deployment.html) section of the
+[deployment](https://osism.tech/docs/testbed#deployment) section of the
 manual.
 
 #### Examples for real deployments