Update cli usage doc to adapt the latest playground (#2586)
Update cli usage doc to adapt the latest playground (#2586)

* Minimize sqlflow:mysql image

* fix ci

* minimize jupyter image size

* modify doc

* change jupyter startup cmd

* add jupyterhub in jupyter image

* set jupyterhub version

* update cli usage doc
sql-machine-learning/sqlflow,sql-machine-learning/sqlflow,sql-machine-learning/sqlflow,sql-machine-learning/sqlflow,sql-machine-learning/sqlflow,sql-machine-learning/sqlflow