Fixing includes

Author: ryanjbaxter

README.adoc

@@ -1869,7 +1869,7 @@ To see the list of all Kubernetes related configuration properties please check
 
 == Building
 
-:jdkversion: 17
+:jdkversion: 1.8
 
 === Basic Compile and Test
 

docs/src/main/asciidoc/spring-cloud-kubernetes.adoc

@@ -45,8 +45,8 @@ To see the list of all Kubernetes related configuration properties please check
 
 == Building
 
-include::https://raw.githubusercontent.com/spring-cloud/spring-cloud-build/master/docs/src/main/asciidoc/building.adoc[]
+include::https://raw.githubusercontent.com/spring-cloud/spring-cloud-build/3.1.x/docs/src/main/asciidoc/building.adoc[]
 
 == Contributing
 
-include::https://raw.githubusercontent.com/spring-cloud/spring-cloud-build/master/docs/src/main/asciidoc/contributing.adoc[]
+include::https://raw.githubusercontent.com/spring-cloud/spring-cloud-build/3.1.x/docs/src/main/asciidoc/contributing.adoc[]