Link to substitutions instead of duplicating the content

docs/features/software-catalog/descriptor-format.md

@@ -98,7 +98,7 @@ See below for details about these fields.
 The descriptor format supports substitutions using `$text`, `$json`, and
 `$yaml`.
 
-Placeholders like `$json: https://example.com/entity.json` are substituded by
+Placeholders like `$json: https://example.com/entity.json` are substituted by
 the content of the referenced file. Files can be referenced from any configured
 integration similar to locations by passing an absolute URL. It's also possible
 to reference relative files like `./referenced.yaml` from the same location.

docs/features/software-catalog/well-known-annotations.md

@@ -238,22 +238,9 @@ annotation, with the same value format.
 
 ### backstage.io/definition-at-location
 
-This annotation allowed to load the API definition from another location. Now
-placeholders can be used instead:
-
-```
-apiVersion: backstage.io/v1alpha1
-kind: API
-metadata:
-  name: petstore
-  description: The Petstore API
-spec:
-  type: openapi
-  lifecycle: production
-  owner: petstore@example.com
-  definition:
-    $text: https://petstore.swagger.io/v2/swagger.json
-```
+This annotation allowed to load the API definition from another location. Use
+[substitution](./descriptor-format.md#substitutions-in-the-descriptor-format)
+instead.
 
 ## Links