* Update api docs (#42725)

* Fix max_pool3d doc, test=document_fix (#42715)

* fix pooling doc

* fix typo test=document_fix

* fix doc typo, test=document_fix

* fix adaptive_avg_pool1d doc bug (#42721)

* fix adaptive_avg_pool1d doc bug

* fix adaptive_avg_pool1d doc bug

* fix spectral_norm en doc (#42728)

* Fix example code bugs (#42739)

* update readme test=document_fix

* fix api docs bugs test=document_fix

* fix code example bugs;test=document_fix
Co-authored-by: NLinjie Chen <40840292+linjieccc@users.noreply.github.com>
Co-authored-by: NWei Shengyu <weisy11@163.com>
Co-authored-by: NWalter <dongshl1226@hotmail.com>
Co-authored-by: Nwangna11BD <79366697+wangna11BD@users.noreply.github.com>

add __all__=[] to python files not in API public list; import * only support in API public list files (#32643)

* update 2.0 public api in nn

* replace Chinese character cause error in ci;synchronization with pr:#32588 to avoid 'ascii' codec in python2

* numbers used in paddle.nn.functional.norm but not imported

* fix code bugs

* fix code bugs test=document_fix

* fix code bugs test=document_fix

* fix examples, test=document_fix

* fix, test=document_fix

As the title

* upgrade comment string to raw string

* fix string in

* fix string with ' '

* revert update on comments

* upgrade only necessary

* fix sample code checker

* fix comments with '''

* fix 2.0api, test=develop

* fix, test=develop

* add weight_norm, test=develop