api-docs: migrate entity filters to entity predicates

Migrated entity filters from deprecated string-based format to the new
entity predicate format in the alpha exports. Also updated documentation
across multiple plugins to use the new format and Blueprint APIs.

Changes:
- Migrated all entity filters in api-docs plugin from strings like
  'kind:api' to entity predicates like { kind: 'api' }
- Updated documentation examples in api-docs, org, kubernetes, and
  catalog-graph plugins
- Migrated all documentation examples from createEntityCardExtension and
  createEntityContentExtension to use EntityCardBlueprint and
  EntityContentBlueprint

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

plugins/kubernetes/README.md

@@ -69,5 +69,11 @@ app:
   extensions:
     - entity-content:kubernetes/kubernetes:
         config:
-          filter: kind:component,api,resource,system
+          filter:
+            kind:
+              $in:
+                - component
+                - api
+                - resource
+                - system
 ```