Adding a few resources

[Stephen Ball]

I am thinking of doing a PR (or 2) to add some other relationships, just want your opinion before I spend any time of it

ConfigMaps
Secrets (maybe also linking to the tls Secrets for ingresses... Not sure if there are any other places that secrets can be related to other than ingresses and used by Pods?)

Second PR

Endpoints (not sure if most people would appreciate this as most people probably don't even know this resource exists between the service and pod). Maybe also changing it to use the convention from the official kubernetes icons style guide, solid arrow line where a resource references another, dotted where it creates? As in deployment creates ReplicaSet, ReplicaSet creates Pod, Service creates Endpoints) I realised you already Service and Endpoints