tidb-in-kubernetes: add local dind deployment doc (#1483)
tidb-in-kubernetes: add local dind deployment doc (#1483)

* tidb-in-kubernetes: migrate local dind deployment doc to docs-cn repo

* update dind introduction

* tidb-in-kubernetes: update wording and format

*  tidb-in-kubernetes: update wording

pingcap/docs-cn,pingcap/docs-cn