Add description for TiKV Ready handled panel (#6375)#6409

ti-chi-bot merged 4 commits into

pingcap:release-5.2pingcap/docs:release-5.2from

ti-chi-bot:cherry-pick-6375-to-release-5.2ti-chi-bot/docs:cherry-pick-6375-to-release-5.2Copy head branch name to clipboard