Remove "Preview" from selectable search parameters

Author: EXPEkesheth

articles/healthcare-apis/fhir/toc.yml

@@ -78,7 +78,7 @@ items:
       href: how-to-run-a-reindex.md
     - name: Search examples
       href: search-samples.md
-    - name: Selectable search parameters (Preview)
+    - name: Selectable search parameters
       href: selectable-search-parameters.md
 - name: FHIR operations
   items: