Fix leading spaces in kubectl commands

This is causing bash/zsh shells to not to record the executed command in the
history. See this link for details: https://unix.stackexchange.com/questions/115917/why-is-bash-not-storing-commands-that-start-with-spaces

Signed-off-by: Ahmet Alp Balkan <ahmetb@google.com>

docs/home/contribute/style-guide.md

@@ -46,7 +46,7 @@ represents.
 
 1. Display information about a pod:
 
-        kubectl describe pod <pod-name>
+       kubectl describe pod <pod-name>
 
     where `<pod-name>` is the name of one of your pods.