The link of prettierrc in CONTRIBUTING.md is error

Created by: mangoGoForward

Describe the bug The link of prettierrc in CONTRIBUTING.md is error, It should link to .prettierrc in the root of project

For UI issues please also add a screenshot that shows the issue.

Versions used(KubeSphere/Kubernetes) KubeSphere: Kubernetes: (If KubeSphere installer used, you can skip this)