Merge pull request #345 from smallstep/carl/intermediate-ca

Reference to `/intermediates.pem` endpoint.

Author: tashian

step-ca/certificate-authority-server-production.mdx

@@ -697,6 +697,9 @@ Generally speaking:
   you can leverage the MDM channel's TLS connection,
   which is established upon MDM enrollment.
 
+The root CA bundle for `step-ca` is available at the `/roots.pem` endpoint,
+and the intermediate CA bundle is available at `/intermediates.pem`.
+
 #### Installing a CA certificate
 
 Your CA certificate may need to be installed and trusted into the target operating system's certificate trust store.