Update README.adoc

Update dependencies in Spring Initializr URL from 'cloud-gateway' to 'cloud-gateway-reactive' to support the RouteLocator demonstrated in the code.

README.adoc

@@ -19,7 +19,7 @@ include::https://raw.githubusercontent.com/spring-guides/getting-started-macros/
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 == Starting with Spring Initializr
 
-You can use this https://start.spring.io/#!type=maven-project&language=java&packaging=jar&jvmVersion=11&groupId=com.example&artifactId=gateway&name=gateway&description=Demo%20project%20for%20Spring%20Boot&packageName=com.example.gateway&dependencies=cloud-gateway,cloud-resilience4j,cloud-contract-stub-runner[pre-initialized project] and click Generate to download a ZIP file. This project is configured to fit the examples in this tutorial.
+You can use this https://start.spring.io/#!type=maven-project&language=java&packaging=jar&jvmVersion=11&groupId=com.example&artifactId=gateway&name=gateway&description=Demo%20project%20for%20Spring%20Boot&packageName=com.example.gateway&dependencies=cloud-gateway-reactive,cloud-resilience4j,cloud-contract-stub-runner[pre-initialized project] and click Generate to download a ZIP file. This project is configured to fit the examples in this tutorial.
 
 To manually initialize the project: