Clalify how to contribute to kubectl book

staging/src/k8s.io/kubectl/docs/book/CONTRIBUTING.md

@@ -4,15 +4,16 @@
 
 ### Fixing Issues
 
-1. Open an Issue
-1. Create a PR
-1. Email PR to sig-cli@googlegroups.com with subject `Kubectl Book: Fix Issue <Issue> in <PR>`
+1. Open an Issue on [kubernetes/kubectl](https://github.com/kubernetes/kubectl/issues) repository
+1. Edit files under [kubernetes/kubernetes/tree/master/staging/src/k8s.io/kubectl/docs/book](https://github.com/kubernetes/kubernetes/tree/master/staging/src/k8s.io/kubectl/docs/book)
+1. Create a PR on [kubernetes/kubernetes](https://github.com/kubernetes/kubernetes) repository
+1. Email PR to kubernetes-sig-cli@googlegroups.com with subject `Kubectl Book: Fix Issue <Issue> in <PR>`
 1. Optional: Come to sig-cli meeting to discuss
 
 ### Adding New Content
 
-1. Open an Issue with proposed content
-1. Email sig-cli@googlegroups.com with subject `Kubectl Book: Proposed Content <Issue>`
+1. Open an Issue with proposed content on [kubernetes/kubectl](https://github.com/kubernetes/kubectl/issues) repository
+1. Email kubernetes-sig-cli@googlegroups.com with subject `Kubectl Book: Proposed Content <Issue>`
 1. Optional: Come to sig-cli meeting to discuss
 
 ## Editing