docs: use upstream schema and recognize the dependency

README.md

@@ -1,9 +1,13 @@
-# Backstage Helm Chart
+# Backstage Helm Chart for OpenShift
 
 [Backstage](https://backstage.io) is an open platform for building developer portals. Powered by a centralized software catalog, Backstage restores order to your microservices and infrastructure and enables your product teams to ship high-quality code quickly — without compromising autonomy.
 
 Backstage unifies all your infrastructure tooling, services, and documentation to create a streamlined development environment from end to end.
 
+**This chart offers an opinionated OpenShift-specific experience.** It is based on and directly depends on an upstream canonical [Backstage Helm chart](https://github.com/backstage/charts/tree/main/charts/backstage). For less opinionated experience, please consider using the upstream chart directly.
+
+This chart extends all the features in the upstream chart in addition to including OpenShift only features. It is not recommended to use this chart on other platforms.
+
 ## Usage
 
 Charts are available in the following formats:

charts/backstage/Chart.yaml

@@ -42,4 +42,4 @@ sources:
 # This is the chart version. This version number should be incremented each time you make changes
 # to the chart and its templates, including the app version.
 # Versions are expected to follow Semantic Versioning (https://semver.org/)
-version: 1.0.2
+version: 1.0.3

charts/backstage/README.md

@@ -1,7 +1,7 @@
 
 # Janus-IDP Backstage Helm Chart
 
-![Version: 1.0.2](https://img.shields.io/badge/Version-1.0.2-informational?style=flat-square) ![Type: application](https://img.shields.io/badge/Type-application-informational?style=flat-square)
+![Version: 1.0.3](https://img.shields.io/badge/Version-1.0.3-informational?style=flat-square) ![Type: application](https://img.shields.io/badge/Type-application-informational?style=flat-square)
 
 A Helm chart for deploying a Backstage application
 
@@ -26,6 +26,10 @@ A Helm chart for deploying a Backstage application
 
 Backstage unifies all your infrastructure tooling, services, and documentation to create a streamlined development environment from end to end.
 
+**This chart offers an opinionated OpenShift-specific experience.** It is based on and directly depends on an upstream canonical [Backstage Helm chart](https://github.com/backstage/charts/tree/main/charts/backstage). For less opinionated experience, please consider using the upstream chart directly.
+
+This chart extends all the features in the upstream chart in addition to including OpenShift only features. It is not recommended to use this chart on other platforms.
+
 ## TL;DR
 
 ```console

charts/backstage/README.md.gotmpl

@@ -20,6 +20,10 @@
 
 Backstage unifies all your infrastructure tooling, services, and documentation to create a streamlined development environment from end to end.
 
+**This chart offers an opinionated OpenShift-specific experience.** It is based on and directly depends on an upstream canonical [Backstage Helm chart](https://github.com/backstage/charts/tree/main/charts/backstage). For less opinionated experience, please consider using the upstream chart directly.
+
+This chart extends all the features in the upstream chart in addition to including OpenShift only features. It is not recommended to use this chart on other platforms.
+
 ## TL;DR
 
 ```console

charts/backstage/values.schema.json

@@ -6,7 +6,7 @@
     "properties": {
         "upstream": {
             "title": "Upstream Backstage chart schema.",
-            "type": "object",
+            "$ref": "https://raw.githubusercontent.com/backstage/charts/main/charts/backstage/values.schema.json",
             "default": {
                 "backstage": {
                     "image": {