fix: add helm repo for coredns (#825)

kubernetes/flux/repositories/helm/coredns.yaml

@@ -0,0 +1,9 @@
+---
+apiVersion: source.toolkit.fluxcd.io/v1beta2
+kind: HelmRepository
+metadata:
+  name: coredns
+  namespace: flux-system
+spec:
+  interval: 1h
+  url: https://coredns.github.io/helm

kubernetes/flux/repositories/helm/kustomization.yaml

@@ -5,6 +5,7 @@ resources:
   - ./bitnami.yaml
   - ./bjw-s.yaml
   - ./cilium.yaml
+  - ./coredns.yaml
   - ./external-dns.yaml
   - ./grafana.yaml
   - ./hajimari.yaml