update private-ca example with proxy details

Author: paigecalvert

docs/reference/embedded-cluster-install.mdx

@@ -145,9 +145,9 @@ Where:
 
 ```bash
 sudo ./APP_SLUG install --license license.yaml --private-ca /path/to/private-ca-bundle \
-  --http-proxy=HOST:PORT \
-  --https-proxy=HOST:PORT \
-  --no-proxy=LIST_OF_HOSTS
+  --http-proxy=http://10.128.0.0:3300 \
+  --https-proxy=http://10.128.0.0:3300 \
+  --no-proxy=123.89.46.4,10.96.0.0/16,*.example.com
 ```
 
 ### Set Admin Console Password