README.md: config in a parent chart.

README.md

@@ -138,6 +138,37 @@ The top-level sections in the `values.yaml` file are:
 The `aserto` umbrella chart's [values.yaml](charts/aserto/values.yaml) file documents the available
 options.
 
+To use the chart as a dependency in your own chart, add the following to the parent chart's `Chart.yaml`:
+```yaml
+dependencies:
+  - name: aserto
+    version: ~0.1.6
+    repository: oci://ghcr.io/aserto-dev/helm
+
+```
+Then run `helm dep update` to download the chart and its dependencies.
+
+When using the `aserto` chart as a dependency the parent's `values.yaml` file should
+keep the `global` values in place but move the other values into the `aserto` section.
+For example:
+```yaml
+global:
+  aserto:
+    ports:
+      grpc: 8282
+      https: 8383
+      health: 8484
+      mertics: 8585
+    ...
+
+aserto:
+  directory:
+    rootDirectory:
+      database:
+        port: 5432
+        ...
+```
+
 ## Deployment
 
 To deploy the Aserto services, first create a `values.yaml` file with the desired configuration.