Update README.md of scaffolder-relation-processor (#5136)

* docs: update README.md of relation processor

Add a note to clarify the relation between this plugin and scaffolder-backend-module-annotator. 

Signed-off-by: Diana Janickova <[email protected]>

* fix: run prettier

Signed-off-by: Diana Janickova <[email protected]>

* mod: update workspace level README.md

Signed-off-by: Diana Janickova <[email protected]>

* mod: generate changeset

Signed-off-by: Diana Janickova <[email protected]>

---------

Signed-off-by: Diana Janickova <[email protected]>

Author: djanickova

workspaces/scaffolder-relation-processor/.changeset/late-bananas-yawn.md

@@ -0,0 +1,5 @@
+---
+'@backstage-community/plugin-catalog-backend-module-scaffolder-relation-processor': patch
+---
+
+Added documentation note clarifying that the plugin only processes existing spec.scaffoldedFrom fields.

workspaces/scaffolder-relation-processor/README.md

@@ -1,10 +1,7 @@
-# [Backstage](https://backstage.io)
+# Scaffolder Relation Processor
 
-This is your newly scaffolded Backstage App, Good Luck!
+This workspace contains a plugin that creates relations between scaffolder templates and the catalog entities they generate.
 
-To start the app, run:
+## Plugins
 
-```sh
-yarn install
-yarn start
-```
+- [catalog-backend-module-scaffolder-relation-processor](./plugins/catalog-backend-module-scaffolder-relation-processor/README.md): Backend module that provides a catalog entity processor to create relations based on the `spec.scaffoldedFrom` field, linking scaffolder templates to their generated entities.

workspaces/scaffolder-relation-processor/plugins/catalog-backend-module-scaffolder-relation-processor/README.md

@@ -32,6 +32,10 @@ backend.start();
 
 Catalog entities containing the `spec.scaffoldedFrom` field will have a relation link be formed between it and the `template` corresponding to the entity ref in the `spec.scaffoldedFrom` field.
 
+> [!NOTE]
+> This plugin only processes entities that **already have** the `spec.scaffoldedFrom` field. It does not add this field to entities. If you are creating new entities through scaffolder templates and expect them to have scaffold relations, you need to ensure that the `spec.scaffoldedFrom` field is added during the scaffolding process.
+> For automatic addition of the `spec.scaffoldedFrom` field, consider using the [`scaffolder-backend-module-annotator`](https://github.com/backstage/community-plugins/tree/main/workspaces/scaffolder-backend-module-annotator) plugin, which provides a `catalog:scaffolded-from` action that can be used in your scaffolder templates to automatically add this field to generated entities.
+
 This link can be viewed in the `relations` field of the Raw YAML view of a catalog entity when inspecting an entity. In the entity with the `spec.scaffoldedFrom` field, the relation type is `scaffoldedFrom` with a target pointing to the value of the `spec.scaffoldedFrom` field. Conversely, for the target template, it will have a relation type of `ScaffolderOf` with a target pointing to the entity with the `spec.scaffoldedFrom` field.
 
 These relations should also appear on the `EntityCatalogGraphView` component from the `@backstage/plugin-catalog-graph` package (only if the entity corresponding to the entity ref exists in the catalog).