docs: cluster auditor arch

Summary

Adding charter Package Architecture Documentation for cluster auditor.

Closes #307 (closed)

charter/packages/cluster-auditor/Architecture.md

+# Cluster Auditor
+
+## Overview
+
+Cluster Auditor pulls data from the kubernetes API, transforms them and inserts them into Elasticsearch which can then be queried by Kibana.  The types of objects are both OPA Gatekeeper CRDS and native kubernetes [objects](https://repo1.dso.mil/platform-one/big-bang/apps/core/cluster-auditor/-/blob/main/chart/templates/configMap.yaml).
+
+## Big Bang Touchpoints
+
+```mermaid
+graph TB 
+  subgraph "Cluster Auditor"
+    clusterauditor 
+  end 
+
+  subgraph "Elasticsearch"
+    clusterauditor --> elasticsearch 
+  end
+```
+
+##High Availability
+
+HA can be configured by increasing the "count" or number of replicas of the [deployment](https://repo1.dso.mil/platform-one/big-bang/apps/core/cluster-auditor/-/blob/main/chart/templates/deployment.yaml).
+
+```yaml
+...
+spec:
+  strategy:
+    type: RollingUpdate
+  selector:
+    matchLabels:
+      engine: fluentd
+  replicas: 1
+...
+```
+
+##Storage
+
+It uses the currently deployed Elasticsearch that's deployed as part of the logging stack.
+
+## Single Sign On (SSO)
+
+CA does not have SSO Integration.
+
+## Licensing
+
+CA parent image is `fluentd` which uses  [Apache License 2.0](https://github.com/fluent/fluentd/blob/master/LICENSE).
+
+## Dependant Packages
+
+- Elasticsearch Kibana
+- OPA Gatekeeper
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