Fix a link to point to real page

The docs were split into github and gitlab forOFC I think, this link
pointed at "self-hosted" which was split into "self-hosted/github" and
"self-hosted/gitlab"

Signed-off-by: Alistair Hey <alistair@heyal.co.uk>

Author: Waterdrips

docs/openfaas-cloud/user-guide.md

@@ -2,7 +2,7 @@
 
 This guide applies to:
 
-* [OpenFaaS Cloud: Self-hosted](/openfaas-cloud/self-hosted/)
+* [OpenFaaS Cloud: Self-hosted](/openfaas-cloud/self-hosted/github)
 * [OpenFaaS Cloud: The Community Cluster](/openfaas-cloud/community-cluster/)
 
 ## The guide