[DOC] Add rename processor documentation

_ingest-pipelines/processors/rename.md

@@ -0,0 +1,97 @@
+---
+layout: default
+title: Rename
+parent: Ingest processors
+nav_order: 200
+---
+
+# Rename processor
+
+The `rename` processor renames a field in the input document. This can be useful when you need to standardize field names or align them with your application's data model.
+
+The following is the syntax for the `rename` processor:
+
+```json
+{
+  "rename": {
+    "field": "source_field_name",
+    "target_field": "target_field_name"
+  }
+}
+```
+{% include copy-curl.html %}
+
+## Configuration parameters
+
+The following table lists the required and optional parameters for the `rename` processor.
+
+Parameter | Required/Optional | Description |
+|-----------|-----------|-----------|
+`field` | Required | The name of the field to be renamed.
+`target_field` | Required | The new name for the field.
+`description` | Optional | Description of the processor's purpose or configuration.
+`if` | Optional | Conditionally execute the processor.
+`ignore_failure` | Optional | Ignore failures for the processor. See Handling pipeline failures.
+`on_failure` | Optional | Handle failures for the processor. See Handling pipeline failures.
+`tag` | Optional | Identifier for the processor. Useful for debugging and metrics.
+
+## Using the processor
+
+Follow these steps to use the processor in a pipeline.
+
+### Step 1: Create a pipeline
+
+The following query creates a pipeline, named <name>, that uses the `rename` processor to <do what?>: 
+
+```json
+<insert pipeline code example>
+```
+{% include copy-curl.html %}
+
+### Step 2 (Optional): Test the pipeline
+
+It is recommended that you test your pipeline before you ingest documents.
+{: .tip}
+
+To test the pipeline, run the following query:
+
+```json
+<insert code example>
+```
+{% include copy-curl.html %}
+
+#### Response
+
+The following example response confirms that the pipeline is working as expected:
+
+```json
+<insert response example>
+```
+
+### Step 3: Ingest a document 
+
+The following query ingests a document into an index named `testindex1`:
+
+```json
+<insert code example>
+```
+{% include copy-curl.html %}
+
+#### Response
+
+The request indexes the document into the index <index name> and will index all documents with <what does this response tell the user?>.
+
+```json
+<insert code example>
+```
+
+### Step 4 (Optional): Retrieve the document
+
+To retrieve the document, run the following query:
+
+```json
+<insert code example>
+```
+{% include copy-curl.html %}
+
+<Provide any other information and code examples relevant to the user or use cases.>