Update docs to mention NoOpTemplateRenderer

Author: markpollack

spring-ai-docs/src/main/antora/modules/ROOT/pages/api/chatclient.adoc

@@ -179,9 +179,15 @@ String answer = ChatClient.create(chatModel).prompt()
     .content();
 ----
 
-Internally, the ChatClient uses the `PromptTemplate` class to handle the user and system text and replace the variables with the values provided at runtime relying on a given `TemplateRenderer` implementation. By default, Spring AI uses the `StTemplateRenderer` implementation, which is based on the open-source https://www.stringtemplate.org/[StringTemplate] engine developed by Terence Parr.
+Internally, the ChatClient uses the `PromptTemplate` class to handle the user and system text and replace the variables with the values provided at runtime relying on a given `TemplateRenderer` implementation.
+By default, Spring AI uses the `StTemplateRenderer` implementation, which is based on the open-source https://www.stringtemplate.org/[StringTemplate] engine developed by Terence Parr.
 
-NOTE: The `TemplateRenderer` configured directly on the `ChatClient` (via `.templateRenderer()`) applies only to the prompt content defined directly in the `ChatClient` builder chain (e.g., via `.user()`, `.system()`). It does *not* affect templates used internally by xref:api/retrieval-augmented-generation.adoc#_questionansweradvisor[Advisors] like `QuestionAnswerAdvisor`, which have their own template customization mechanisms (see xref:api/retrieval-augmented-generation.adoc#_custom_template[Custom Advisor Templates]).
+Spring AI also provides a `NoOpTemplateRenderer` for cases where no template processing is desired.
+
+Spring AI also provides a `NoOpTemplateRenderer`.
+
+NOTE: The `TemplateRenderer` configured directly on the `ChatClient` (via `.templateRenderer()`) applies only to the prompt content defined directly in the `ChatClient` builder chain (e.g., via `.user()`, `.system()`).
+It does *not* affect templates used internally by xref:api/retrieval-augmented-generation.adoc#_questionansweradvisor[Advisors] like `QuestionAnswerAdvisor`, which have their own template customization mechanisms (see xref:api/retrieval-augmented-generation.adoc#_custom_template[Custom Advisor Templates]).
 
 If you'd rather use a different template engine, you can provide a custom implementation of the `TemplateRenderer` interface directly to the ChatClient. You can also keep using the default `StTemplateRenderer`, but with a custom configuration.
 

spring-ai-docs/src/main/antora/modules/ROOT/pages/api/prompt.adoc

@@ -141,6 +141,24 @@ public interface TemplateRenderer extends BiFunction<String, Map<String, Object>
 }
 ----
 
+Spring AI uses the `TemplateRenderer` interface to handle the actual substitution of variables into the template string.
+The default implementation uses <<StringTemplate>>.
+You can provide your own implementation of `TemplateRenderer` if you need custom logic.
+For scenarios where no template rendering is required (e.g., the template string is already complete), you can use the provided `NoOpTemplateRenderer`.
+
+.Example using a custom StringTemplate renderer with '<' and '>' delimiters
+[source,java]
+----
+PromptTemplate promptTemplate = PromptTemplate.builder()
+    .renderer(StTemplateRenderer.builder().startDelimiterToken('<').endDelimiterToken('>').build())
+    .template("""
+            Tell me the names of 5 movies whose soundtrack was composed by <composer>.
+            """)
+    .build();
+
+String prompt = promptTemplate.render(Map.of("composer", "John Williams"));
+----
+
 The interfaces implemented by this class support different aspects of prompt creation:
 
 `PromptTemplateStringActions` focuses on creating and rendering prompt strings, representing the most basic form of prompt generation.