Clarify documentation on @AutoConfigureRestDocs with WebTestClient

Closes gh-15977

Author: wilkinsona

spring-boot-project/spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc

@@ -6903,7 +6903,7 @@ It can also be used to configure the host, scheme, and port that appears in any
 
 [[boot-features-testing-spring-boot-applications-testing-autoconfigured-rest-docs-mock-mvc]]
 ===== Auto-configured Spring REST Docs Tests with Mock MVC
-`@AutoConfigureRestDocs` customizes the `MockMvc` bean to use Spring REST Docs.
+`@AutoConfigureRestDocs` customizes the `MockMvc` bean to use Spring REST Docs when testing Servlet-based web applications.
 You can inject it by using `@Autowired` and use it in your tests as you normally would when using Mock MVC and Spring REST Docs, as shown in the following example:
 
 [source,java,indent=0]
@@ -6973,7 +6973,7 @@ The following example shows a `RestDocumentationResultHandler` being defined:
 
 [[boot-features-testing-spring-boot-applications-testing-autoconfigured-rest-docs-web-test-client]]
 ===== Auto-configured Spring REST Docs Tests with WebTestClient
-`@AutoConfigureRestDocs` can also be used with `WebTestClient`.
+`@AutoConfigureRestDocs` can also be used with `WebTestClient` when testing reactive web applications.
 You can inject it by using `@Autowired` and use it in your tests as you normally would when using `@WebFluxTest` and Spring REST Docs, as shown in the following example:
 
 [source,java,indent=0]

spring-boot-project/spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/restdocs/AutoConfigureRestDocs.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,16 +23,25 @@
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
+import io.restassured.RestAssured;
+
 import org.springframework.boot.autoconfigure.ImportAutoConfiguration;
 import org.springframework.boot.test.autoconfigure.properties.PropertyMapping;
 import org.springframework.context.annotation.Import;
 import org.springframework.core.annotation.AliasFor;
+import org.springframework.test.web.reactive.server.WebTestClient;
+import org.springframework.test.web.servlet.MockMvc;
 
 /**
  * Annotation that can be applied to a test class to enable and configure
- * auto-configuration of Spring REST Docs. Allows configuration of the output directory
- * and the host, scheme, and port of generated URIs. When further configuration is
- * required a {@link RestDocsMockMvcConfigurationCustomizer} bean can be used.
+ * auto-configuration of Spring REST Docs. The auto-configuration sets up
+ * {@link MockMvc}-based testing of a servlet web application, {@link WebTestClient}-based
+ * testing of a reactive web application, or {@link RestAssured}-based testing of any web
+ * application over HTTP.
+ * <p>
+ * Allows configuration of the output directory and the host, scheme, and port of
+ * generated URIs. When further configuration is required a
+ * {@link RestDocsMockMvcConfigurationCustomizer} bean can be used.
  *
  * @author Andy Wilkinson
  * @since 1.4.0