DOC-13246: Sync Gateway 3.3 Partitioned Indexes Feature (#864)

* Update Indexing page to de-emphasize Views
* Document partitioned indexes
* Deprecate num_index_replicas → index.num_replicas
* Rebuild Redocly documentation
* Updates after review

Author: simon-dew

modules/ROOT/assets/attachments/bundled-admin.yaml

@@ -1,12 +1,12 @@
 openapi: 3.0.3
 info:
-  version: '3.2'
   title: Sync Gateway Metrics REST API
   description: |-
     # Introduction
 
     Sync Gateway manages access and synchronization between Couchbase Lite and Couchbase Server.
     The Sync Gateway Metrics REST API returns Sync Gateway metrics, in JSON or Prometheus-compatible formats, for performance monitoring and diagnostic purposes.
+  version: '3.3'
   license:
     name: Business Source License 1.1 (BSL)
     url: https://github.com/couchbase/sync_gateway/blob/master/LICENSE
@@ -49,15 +49,6 @@ paths:
       tags:
         - Server
       operationId: get__ping
-    head:
-      responses:
-        '200':
-          description: Server is available
-      tags:
-        - Server
-      summary: Check if API is available
-      description: Returns OK status if API is available.
-      operationId: head__ping
   /metrics:
     get:
       summary: Get debugging and monitoring runtime stats in Prometheus Exposition format
@@ -78,6 +69,8 @@ paths:
         - Prometheus
       operationId: get_metrics
   /_expvar:
+    tags:
+      - JSON
     get:
       summary: Get all Sync Gateway statistics in JSON format
       description: |-