Merge pull request #4472 from backstage/iameap/clarify-search-architecture

[Search] Clarify search architecture

docs/features/search/architecture.md

@@ -20,7 +20,10 @@ Backstage end-users.
 At a base-level, we want to support the following:
 
 - We aim to enable the capability to search across the entire Backstage
-  ecosystem by decoupling search from content management.
+  ecosystem including, but not limited to, entities in the software catalog.
+  Searchable content won't be required to relate directly to the software
+  catalog, but by convention, we may encourage loose relationships using
+  well-known field names or attributes.
 - We aim to enable the capability to deploy Backstage using any search engine,
   by providing an integration and translation layer between the core search
   plugin and search engine specific logic that can be extended for different
@@ -37,3 +40,9 @@ More advanced use-cases we hope to support with this architecture include:
 - It should be possible to customize the search UI
 - It should be possible to add search functionality to any Backstage plugin or
   deployment
+
+Architecture non-goals:
+
+- At this time, we do not intend to directly support event-driven or incremental
+  index management. Instead, we'll be focused on scheduled, bulk index
+  management.