Document the DefaultServlet is no longer being enabled by default

See gh-32004

Author: ionascustefanciprian

spring-boot-project/spring-boot-docs/src/docs/asciidoc/web/servlet.adoc

@@ -127,7 +127,17 @@ If you set the configprop:spring.mvc.message-codes-resolver-format[] property `P
 By default, Spring Boot serves static content from a directory called `/static` (or `/public` or `/resources` or `/META-INF/resources`) in the classpath or from the root of the `ServletContext`.
 It uses the `ResourceHttpRequestHandler` from Spring MVC so that you can modify that behavior by adding your own `WebMvcConfigurer` and overriding the `addResourceHandlers` method.
 
-In a stand-alone web application, the default servlet from the container is also enabled and acts as a fallback, serving content from the root of the `ServletContext` if Spring decides not to handle it.
+In a stand-alone web application, default servlet is not enabled. It can be enabled as follows:
+
+
+[source,yaml,indent=0,subs="verbatim",configprops,configblocks]
+----
+    server:
+        servlet:
+            register-default-servlet: true
+----
+
+If the default servlet is enablend it acts as a fallback, serving content from the root of the `ServletContext` if Spring decides not to handle it.
 Most of the time, this does not happen (unless you modify the default MVC configuration), because Spring can always handle requests through the `DispatcherServlet`.
 
 By default, resources are mapped on `+/**+`, but you can tune that with the configprop:spring.mvc.static-path-pattern[] property.