Polish "Clarify deployment of Spring Boot apps to App Engine Standard"

See gh-13090

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

@@ -400,10 +400,12 @@ identifier for you and also sets up HTTP routes. Add a Java app to the project a
 it empty and then use the https://cloud.google.com/sdk/downloads[Google Cloud SDK] to
 push your Spring Boot app into that slot from the command line or CI build.
 
-App Engine Standard requires one to use WAR packaging. Follow https://github.com/GoogleCloudPlatform/getting-started-java/blob/master/appengine-standard-java8/springboot-appengine-standard/README.md[these steps] to deploy App Engine Standard application to Google Cloud.
+App Engine Standard requires you to use WAR packaging. Follow
+https://github.com/GoogleCloudPlatform/getting-started-java/blob/master/appengine-standard-java8/springboot-appengine-standard/README.md[these steps]
+to deploy App Engine Standard application to Google Cloud.
 
-App Engine Flex on the other hand requires you to create an `app.yaml` file to describe 
+Alternatively, App Engine Flex requires you to create an `app.yaml` file to describe
-the resources your app requires. Normally, you put this file in `src/main/appengine`, 
+the resources your app requires. Normally, you put this file in `src/main/appengine`,
 and it should resemble the following file:
 
 [source,yaml,indent=0]