chore: documented Spring add-on excludeUrls parameter

Closes vaadin/flow#15762

articles/integrations/spring/configuration.asciidoc

@@ -40,6 +40,22 @@ vaadin.whitelisted-packages=com/foo/myapp/ui,com/foo/components
 You should use either `whitelisted-packages` or `blacklisted-packages`.
 If both of them have values, `blacklisted-packages` is ignored.
 
+=== Prevent Handling of specific URLs
+
+For some use cases, it is desirable to exclude specific URLs from being handled by Vaadin, without changing the Vaadin URL mapping.
+For example, to integrate Swagger-UI, Vaadin should not handle requests for resource accessed by `/swagger-ui.html`.
+
+The list of URL patterns that should not be handled by the Vaadin servlet can be configured using the `vaadin.exclude-urls` property, in the form of a comma-separated string.
+
+.application.properties
+[source,properties]
+----
+vaadin.exclude-urls=/swagger-ui/**,/custom-service/**
+----
+
+[NOTE]
+This configuration only applies when the Vaadin servlet is mapped to the root mapping.
+
 === Launch the Browser Automatically in Development Mode
 
 You can configure a Spring Boot project to launch the default browser automatically when starting the application in development mode via the following property: