Add help message in doc:go-client-api.md (#4763)
Add help message in doc:go-client-api.md (#4763)

* add help message in doc:go-client-api.md

Signed-off-by: yy <ac9f00142fff53086aaf5bfc24b2d428e023096b@qq.com>

* update go-client-api.md

Signed-off-by: yy <ac9f00142fff53086aaf5bfc24b2d428e023096b@qq.com>

BusyJay/tikv,pingcap/tikv,pingcap/tikv,BusyJay/tikv,c4pt0r/tikv,BusyJay/tikv,BusyJay/tikv