{{ requiredEnv "RELEASE_NAME" }} used in the file values.example.yaml in monochart

`{{ requiredEnv "RELEASE_NAME" }}` used in the file values.example.yam in monochartl, but I think this is typically a Helmfile-thing and can't be used in a Helm values file.

```
[...]
affinity:
# use of simple rule
affinityRule: "ShouldBeOnDifferentNode"
# use custom affinity rule. Here app MUST be on different host then postgres instance for it
podAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
- labelSelector:
matchExpressions:
- key: app
operator: In
values:
- postgresql
- key: release
operator: In
values:
- "{{ requiredEnv "RELEASE_NAME" }}-postgresql"
topologyKey: "kubernetes.io/hostname"
```