Add test instructions as Markdown comments

docs/user/openstack/observability.md

@@ -37,6 +37,25 @@ sum by (vm_instance) (
 
 ## Using remote-write to send RHOSO and OCP metrics to an external storage
 
+<!--
+
+To generate test certificates:
+
+```bash
+# Generate a CA if you don't have one already
+openssl genrsa -out ca.key 4096
+openssl req -batch -new -x509 -key ca.key -out ca.crt
+
+# Generate the client certificates and sign them:
+for target in server ocp-client osp-client; do
+    openssl genrsa -out "${target}.key" 4096
+    openssl req -batch -new -key "${target}.key" -out "${target}.csr"
+    openssl x509 -req -CA ca.crt -CAkey ca.key -CAcreateserial -in "${target}.csr" -out "${target}.crt"
+done
+```
+
+-->
+
 ### Step 1: Set up the external storage
 
 In this example, we'll assume that the external storage is another Prometheus instance.