[DOCS] Adds docs to built-in and Eland model support in Inference API.

docs/reference/inference/put-inference.asciidoc

@@ -6,10 +6,11 @@ experimental[]
 
 Creates a model to perform an {infer} task.
 
-IMPORTANT: The {infer} APIs enable you to use certain services, such as ELSER, 
-OpenAI, or Hugging Face, in your cluster. This is not the same feature that you 
-can use on an ML node with custom {ml} models. If you want to train and use your 
-own model, use the <<ml-df-trained-models-apis>>.
+IMPORTANT: The {infer} APIs enable you to use certain services, such as built-in 
+{ml} models (ELSER, E5), models uploaded through Eland, Cohere, OpenAI, or 
+Hugging Face, in your cluster. This is not the same feature that you can use on 
+an ML node with custom {ml} models. If you want to train and use your own model, 
+use the <<ml-df-trained-models-apis>>.
 
 
 [discrete]
@@ -39,6 +40,7 @@ The following services are available through the {infer} API:
 * ELSER
 * Hugging Face
 * OpenAI
+* text embedding (for E5 and models uploaded through Eland)
 
 
 [discrete]
@@ -70,6 +72,8 @@ Available services:
 * `hugging_face`: specify the `text_embedding` task type to use the Hugging Face 
 service.
 * `openai`: specify the `text_embedding` task type to use the OpenAI service.
+* `text_embedding`: specify the `text_embedding` task type to use the E5 
+built-in model or text embedding models uploaded by Eland.
 
 `service_settings`::
 (Required, object)
@@ -164,6 +168,26 @@ https://platform.openai.com/account/organization[**Settings** > **Organizations*
 The URL endpoint to use for the requests. Can be changed for testing purposes.
 Defaults to `https://api.openai.com/v1/embeddings`.
 =====
++
+.`service_settings` for `text_embedding`
+[%collapsible%closed]
+=====
+`model_id`::
+(Required, string)
+The name of the text embedding model to use for the {infer} task. It can be the 
+ID of either a built-in model (for example, `.multilingual-e5-small` for E5) or 
+a text embedding model 
+{ml-docs}/ml-nlp-import-model.html#ml-nlp-import-script[uploaded through Eland].
+
+`num_allocations`:::
+(Required, integer)
+The number of model allocations to create. 
+
+`num_threads`:::
+(Required, integer)
+The number of threads to use by each model allocation.
+=====
+
 
 `task_settings`::
 (Optional, object)
@@ -234,6 +258,31 @@ PUT _inference/text_embedding/cohere-embeddings
 // TEST[skip:TBD]
 
 
+[discrete]
+[[inference-example-e5]]
+===== E5 via the text embedding service
+
+The following example shows how to create an {infer} model called
+`my-e5-model` to perform a `text_embedding` task type.
+
+[source,console]
+------------------------------------------------------------
+PUT _inference/text_embedding/my-e5-model
+{
+  "service": "text_embedding",
+  "service_settings": {
+    "num_allocations": 1,
+    "num_threads": 1,
+    "model_id": ".multilingual-e5-small" <1>
+  }
+}
+------------------------------------------------------------
+// TEST[skip:TBD]
+<1> The `model_id` must be the ID of one of the built-in E5 models. Valid values 
+are `.multilingual-e5-small` and `.multilingual-e5-small_linux-x86_64`. For 
+further details, refer to the {ml-docs}/ml-nlp-e5.html[E5 model documentation].
+
+
 [discrete]
 [[inference-example-elser]]
 ===== ELSER service
@@ -304,6 +353,29 @@ endpoint URL. Select the model you want to use on the new endpoint creation page
 task under the Advanced configuration section. Create the endpoint. Copy the URL 
 after the endpoint initialization has been finished.
 
+[discrete]
+[[inference-example-eland]]
+===== Models uploaded by Eland via the text embedding service
+
+The following example shows how to create an {infer} model called
+`my-text-embedding-model` to perform a `text_embedding` task type.
+
+[source,console]
+------------------------------------------------------------
+PUT _inference/text_embedding/my-msmarco-minilm-model
+{
+  "service": "text_embedding",
+  "service_settings": {
+    "num_allocations": 1,
+    "num_threads": 1,
+    "model_id": "msmarco-MiniLM-L12-cos-v5" <1>
+  }
+}
+------------------------------------------------------------
+// TEST[skip:TBD]
+<1> The `model_id` must be the ID of a text embedding model 
+{ml-docs}/ml-nlp-import-model.html#ml-nlp-import-script[uploaded through Eland].
+
 
 [discrete]
 [[inference-example-openai]]