feature: capability to add extra kubernetes manifests

example usage:

```yaml
extraManifests:
  - apiVersion: v1
    kind: LimitRange
    metadata:
      annotations:
        argocd.argoproj.io/sync-wave: "10"
      name: default-limit-range
    spec:
      limits:
      - default:
          memory: 700Mi
        defaultRequest:
          cpu: 50m
          memory: 500Mi
        type: Container
```

charts/py-app/templates/extra-objects.yaml

@@ -0,0 +1,6 @@
+{{- if .Values.extraManifests }}
+{{- range .Values.extraManifests }}
+---
+{{ toYaml . }}
+{{- end }}
+{{- end }}

charts/py-app/values.yaml

@@ -125,3 +125,5 @@ autoscaling:
   maxReplicas: 20
   targetCPUUtilizationPercentage: 80
   # targetMemoryUtilizationPercentage: 80
+
+extraManifests: []