OSDOS-1890: Updated two Azure links in the contribution doc.

Author: EricPonvelle

contributing_to_docs/doc_guidelines.adoc

@@ -532,13 +532,13 @@ URIs beginning with `http` are forbidden for security reasons and will fail the
 documentation build.
 ====
 
-For example, if you want to embed the link:https://github.com/openshift/installer/blob/release-4.7/upi/azure/01_vnet.json[01_vnet.json] template, include the URI of its raw file version like this:
+For example, if you want to embed the link:https://github.com/openshift/installer/blob/release-4.8/upi/azure/01_vnet.json[01_vnet.json] template, include the URI of its raw file version like this:
 
 ```
 .`01_vnet.json` ARM template
 [source,json]
 ----
-\include::https://raw.githubusercontent.com/openshift/installer/release-4.7/upi/azure/01_vnet.json[]
+\include::https://raw.githubusercontent.com/openshift/installer/release-4.8/upi/azure/01_vnet.json[]
 ----
 ```