docs: delete unused file that causes confusion (#15910)

docs/development/experimental-features.md

@@ -1,59 +0,0 @@
----
-id: experimental-features
-title: "Experimental features"
----
-
-<!--
-  ~ Licensed to the Apache Software Foundation (ASF) under one
-  ~ or more contributor license agreements.  See the NOTICE file
-  ~ distributed with this work for additional information
-  ~ regarding copyright ownership.  The ASF licenses this file
-  ~ to you under the Apache License, Version 2.0 (the
-  ~ "License"); you may not use this file except in compliance
-  ~ with the License.  You may obtain a copy of the License at
-  ~
-  ~   http://www.apache.org/licenses/LICENSE-2.0
-  ~
-  ~ Unless required by applicable law or agreed to in writing,
-  ~ software distributed under the License is distributed on an
-  ~ "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
-  ~ KIND, either express or implied.  See the License for the
-  ~ specific language governing permissions and limitations
-  ~ under the License.
-  -->
-
-The following features are marked [experimental](./experimental.md) in the Druid docs.
-
-This document includes each page that mentions an experimental feature. To graduate a feature, remove all mentions of its experimental status on all relevant pages.
-
-Note that this document does not track the status of contrib extensions, all of which are considered experimental.
-
-## SQL-based ingestion
-
-- [SQL-based ingestion](../multi-stage-query/index.md)
-- [SQL-based ingestion concepts](../multi-stage-query/concepts.md)
-- [SQL-based ingestion and multi-stage query task API](../api-reference/sql-ingestion-api.md)
-
-## Indexer service
-
-- [Indexer service](../design/indexer.md)
-- [Data server](../design/architecture.md#indexer-service-optional)
-
-## Kubernetes
-
-- [Kubernetes](../development/extensions-core/kubernetes.md)
-
-## Segment locking
-
-- [Configuration reference](../configuration/index.md#overlord-operations)
-- [Task reference](../ingestion/tasks.md#locking)
-- [Design](../design/storage.md#availability-and-consistency)
-
-## Front coding
-
-- [Ingestion spec reference](../ingestion/ingestion-spec.md#front-coding)
-
-## Other configuration properties
-
-- [Configuration reference](../configuration/index.md)
-   - `CLOSED_SEGMENTS_SINKS` mode

docs/querying/sql.md

@@ -90,7 +90,7 @@ documentation.
 ## PIVOT
 
 :::info
-The PIVOT operator is an [experimental feature](../development/experimental-features.md).
+The PIVOT operator is an [experimental feature](../development/experimental.md).
 :::
 
 The PIVOT operator carries out an aggregation and transforms rows into columns in the output.
@@ -147,7 +147,7 @@ LIMIT 15
 ## UNPIVOT
 
 :::info
-The UNPIVOT operator is an [experimental feature](../development/experimental-features.md).
+The UNPIVOT operator is an [experimental feature](../development/experimental.md).
 :::
 
 The UNPIVOT operator transforms existing column values into rows.