fix paddle.Model cn docs (#4929)

* use copy-from instead of copy, test=document_fix

* fix log_freq default value (PaddlePaddle/Paddle#43343), test=document_fix

* add space between cn and en char, test=document_fix

* add `optional`, test=document_fix

* add missing parameters, test=document_fix

* remove extra parameters, test=document_fix

* add missing links for `ProgBarLogger` and `ModelCheckpoint`, test=document_fix

* update stack_outputs desc, test=document_fix

* None -> 无, test=document_fix

* fix some parameters, test=document_fix

* resolve conflicts

Author: SigureMo