feat: addon rss forwarder (#876)

Co-authored-by: Devin Buhl <onedr0p@users.noreply.github.com>

bootstrap/templates/addons/discord-template-notifier/app/secret.sops.yaml.j2

@@ -0,0 +1,15 @@
+---
+apiVersion: v1
+kind: Secret
+metadata:
+  name: discord-template-notifier-secret
+  namespace: default
+type: Opaque
+stringData:
+  config.toml: |-
+    [feeds.github-template]
+    url = "https://github.com/onedr0p/flux-cluster-template/commits/main/.atom"
+    interval = "10m"
+    retry_limit = 5
+    sink.type = "discord"
+    sink.url = "{{ discord_template_notifier.webhook_url }}"