Docs: add deprecation note for normalization and custom transformation (#35275)

Author: marcosmarxm

docs/operator-guides/transformation-and-normalization/transformations-with-airbyte.md

@@ -4,6 +4,12 @@ products: oss-*
 
 # Transformations with Airbyte (Part 3/3)
 
+:::warning
+Normalization and Custom Transformation are deprecated features. 
+Destinations using Normalization will be replaced by [Typing and Deduping](/using-airbyte/core-concepts/typing-deduping.md).
+Custom Transformation will be removed on March 31. For more information, visit [here](https://github.com/airbytehq/airbyte/discussions/34860).
+:::
+
 This tutorial will describe how to push a custom dbt transformation project back to Airbyte to use during syncs.
 
 This guide is the last part of the tutorial series on transformations, following [Transformations with SQL](transformations-with-sql.md) and [connecting EL with T using dbt](transformations-with-dbt.md).

docs/operator-guides/transformation-and-normalization/transformations-with-dbt.md

@@ -4,6 +4,12 @@ products: oss-*
 
 # Transformations with dbt (Part 2/3)
 
+:::warning
+Normalization and Custom Transformation are deprecated features. 
+Destinations using Normalization will be replaced by [Typing and Deduping](/using-airbyte/core-concepts/typing-deduping.md).
+Custom Transformation will be removed on March 31. For more information, visit [here](https://github.com/airbytehq/airbyte/discussions/34860).
+:::
+
 This tutorial will describe how to integrate SQL based transformations with Airbyte syncs using specialized transformation tool: dbt.
 
 This tutorial is the second part of the previous tutorial [Transformations with SQL](transformations-with-sql.md). Next, we'll wrap-up with a third part on submitting transformations back in Airbyte: [Transformations with Airbyte](transformations-with-airbyte.md).

docs/operator-guides/transformation-and-normalization/transformations-with-sql.md

@@ -4,6 +4,12 @@ products: oss-*
 
 # Transformations with SQL (Part 1/3)
 
+:::warning
+Normalization and Custom Transformation are deprecated features. 
+Destinations using Normalization will be replaced by [Typing and Deduping](/using-airbyte/core-concepts/typing-deduping.md).
+Custom Transformation will be removed on March 31. For more information, visit [here](https://github.com/airbytehq/airbyte/discussions/34860).
+:::
+
 This tutorial will describe how to integrate SQL based transformations with Airbyte syncs using plain SQL queries.
 
 This is the first part of ELT tutorial. The second part goes deeper with [Transformations with dbt](transformations-with-dbt.md) and then wrap-up with a third part on [Transformations with Airbyte](transformations-with-airbyte.md).