[HUDI-2319] dbt example models to demonstrate hudi dbt integration (#5220)

* dbt example models to demonstrate hudi dbt integration

* Fixed readme text

hudi-examples/hudi-examples-dbt/models/example/hudi_insert_table.sql

@@ -0,0 +1,42 @@
+/*
+ * 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.
+ *
+ */
+
+/*
+ Example of an insert for a non-partitioned table with incremental materialization.
+ */
+{{
+    config(
+        materialized='incremental',
+        file_format='hudi',
+        unique_key='id'
+    )
+}}
+
+with source_data as (
+
+    select format_number(rand()*1000, 0) as id
+    union all
+    select null as id
+
+    )
+
+select *
+from source_data
+where id is not null