Merge pull request #5284 from ramnar/patch-2

Added Codebase Tour Video

Author: k8s-ci-robot

sig-cli/CONTRIBUTING.md

@@ -82,6 +82,7 @@ work.
   - [kubernetes/cmd/kubectl] is the entry point
   - [kubernetes/pkg/kubectl] is the implementation
   - Look at how some of the other commands are implemented
+  - [Codebase Tour]
 - Try adding a new command to do something simple:
   - Add `kubectl hello-world`: print "Hello World"
   - Add `kubectl hello-kubernetes -f file`: Print "Hello \<kind of resource\> \<name of resource\>"
@@ -415,6 +416,7 @@ See the sig-cli [community page] for points of contact and meeting times:
 [kubectl docs]: https://kubernetes.io/docs/tutorials/object-management-kubectl/object-management/
 [kubernetes/cmd/kubectl]: https://git.k8s.io/kubernetes/cmd/kubectl
 [kubernetes/pkg/kubectl]: https://git.k8s.io/kubernetes/pkg/kubectl
+[Codebase Tour]:  https://youtu.be/eZeCFRh2uGg?t=538
 [leads]: /sig-cli/README.md#leadership
 [management overview]: https://kubernetes.io/docs/concepts/tools/kubectl/object-management-overview
 [meeting]: /sig-cli/README.md#meetings