docs: fix format issue for Contributor Guide
docs: fix format issue for Contributor Guide

warmchang/minikube,warmchang/minikube,kubernetes/minikube,warmchang/minikube,kubernetes/minikube,warmchang/minikube,kubernetes/minikube,kubernetes/minikube,warmchang/minikube,kubernetes/minikube,kubernetes/minikube,warmchang/minikube,warmchang/minikube,kubernetes/minikube