* Fix several api docs

test=develop, test=document_fix

refine en api doc of [shape, scale, split, selu, soft_relu, scatter], test=develop, test=document_fix (#20264)

* fix the reduce api en doc test=document_fix test=develop

* fix the fluid.data test=develop test=document_fix

* fix the API.spec test=develop test=document_fix

* fix according the review test=develop test=document_fix

* fix the confilict test=develop test=document_fix

* fix en doc train_from_dataset and infer_from_datatset

* update English document, test=document_fix

* update api.spec, test=document_fix

* update api.spec, test=document_fix

* update, test=document_fix

* update the api en_doc of has_inf, has_nan, cumsum, double_buffer and mul, test=document_fix

* update the API.spec for apis, test=document_fix

* test=develop, fix docker with paddle nccl problem

* test=develop, refine en_doc for Variable and Program

* test=document_fix, fix English doc for Variable and Program

* test=document_fix, refine astype code block style

* test=document_fix, add example code for Variable properties

* test=document_fix, fix BackwardStrategy English Doc

* test=document_fix, fix syntax

* test=document_fix, refresh API.spec

* test=document_fix, refine api spec

* test=document_fix, refine api spec

* fix expand bug test=develop

* fix style test=develop

* fix style test=develop

* fix style test=develop

* fix style test=develop

* modify WeightNormParamAttr English doc test=develop

* modify map_reader en test=develop

* fix fluid.data
test=document_fix

* fix doc batch dim
test=document_fix

Fix parse content in CreatePreLoadReaders. Before this fix, if you use dataset.set_parse_content and dataset.preload, parse content didn't work.

* polish en doc, test=document_fix, test=develop

* update sample code, test=document_fix, test=develop

* fix sample typo, test=document_fix, test=develop

* refine name_scope document

test=develop test=document_fix

* update name_scope API.spec

test=develop test=document_fix

* Leave fake quantization around mul

* Replace Fake with Real Quantized Mul

* Gather all scales from fake_quantize_ops

* Enable uint8 in conv_relu tensors

* Disable int8 mul and restore fake mul

* Fix buf for running QAT on VGG16 and 19

* modify document of 11 APIs
test=develop
test=document_fix

* fix dtype to data type and description of name parameter

* update norm op, test=develop, test=document_fix

* fix norm api, test=develop, test=document_fix

* refine en doc. test=develop. test=document_fix

* Refine StaticRNN api-doc-en

* refine static rnn doc

* refine api doc of fluid.data

* refine api doc from commends

* refine api.spec

* Refine grammer

Fix english doc api, invloves the op of retinanet_target_assign, sigmoid_focal_loss and retinanet_detection_output. (#20250)

* test=document_fix
test=develop
Fix english doc api, invloves the op of retinanet_target_assign, sigmoid_focal_loss and retinanet_detection_output.

* test=document_fix
test=develop
remove Notice: this OP supports CPU mode only in english doc api of retinanet_target_assign and retinanet_detection_output

* test=document_fix
test=develop
fix API Difference for retinanet_target_assign and retinanet_detection_output

* fix API.spec conflicts in english doc api of retinanet_target_assign, sigmoid_focal_loss,  retinanet_detection_output
test=develop
test=document_fix

* fix API.spec conflicts in english doc api of retinanet_target_assign, sigmoid_focal_loss, retinanet_detection_output
test=develop
test=document_fix

* refine profiler document

test=develop test=document_fix

* update profiler document

test=develop test=document_fix

* test=document_fix
Fix english doc api, invloves the op of greater_equal,greater_than,less_equal,not_equal,
rank,rsqrt,diag,linspace,reduce_all,reduce_any,sign,where,zeros_like,unique_with_counts.

* Fix some format problem in the op of sign and greather_than.
test=develop
test=document_fix

* Fix the example of zeros_like, and update api.spec
test=develop
test=document_fix

* add new save load interface; test=develop

* add new save interface; test=develop

* add save load interface ;

* fix save load error;

* fix dygraph set dict bug;

* add save load unit test; test=develop

* fix test_imperative_optimizer bug; test=develop

* fix unitest optimizer bug; test=develop

* fix code coverage; test=develop

* fix converage; test=develop

* add document for apis; test=develop

* fix unitest error; test=develop

* fix save load unit test error; test=develop

* fix error message; test=develop

* change set_parameter set_optimizer to save_dygraph; test=develop

* add load_graph check; test=develop

* fix api spec; test=develop

* test=develop, fix docker with paddle nccl problem

* test=develop, refine en_doc for Variable and Program

* test=document_fix, fix English doc for Variable and Program

* test=document_fix, refine astype code block style

* test=document_fix, add example code for Variable properties

* polish en api,test=develop,test=document_fix

* modified api.spec, test=develop,test=document_fix

* modified ops for arc,test=develop,test=document_fix

* update for 1.6, test=develop,test=document_fix

* update API.spec

* Update API.spec

test=develop,test=document_fix

* Update API.spec

test=develop,test=document_fix

* refine Normal Uniform documnet

* Polish en doc of LoDTensorArray, test=develop, test=document_fix

* follow comments, test=develop, test=document_dix

* fix fluid.data code example, test=develop, test=document_preview, test=document_fix