Remove unnecessary "if statement".

* fix merge ci

* make timeout larger

* tmp test merge

* debug

* sleep 1 in optimizer ut

* skip test clip grad

* skip test clip grad

* fix merge ci

* [Feature] Support convert BN to SyncBN by config

* make unit test compatible with cpu

* Fix as comment

* fix unit test

* change signature of convert_sync_batchnorm: rename sync_bn to implemention

* fix unit test

* fix unit test

* fix merge ci

* make timeout larger

* [Docs] Fix api files of en docs

* minor fix

* fix ema load_state_dict

* fix ema load_state_dict

* fix for test

* fix by review

* fix resume and keys

* wandb define_metric

* fix docs

* add wandb docs link

* Add dockerfile

* update README

* resolve comments

* Remove unnecessary commands

* Simplify the dockerfile

* enable to specific mmengine version

* Update README.md

* revert

* bugfix wandb image

* del judged

* use self._wandb

* [CI] Update Github Action CI and CircleCI

* clear outdated commands in CI

* clear outdated commands in CI

* add '-r' when installing packages from txt

* update

* update circleci

* fix mismatch conflicts

* update

* install system dependencies

* update

* set env

* fix ut

* update cuda version on Windows

* update push action

* [Docs] Fix outdated index

* update index.rst

* fix readme url

* update readme

* fix typos

* [Docs] Add readthedocs.yml

* include torch in readthedocs.yml

* add torch torchvision in docs.txt

* [WIP] Refactor-docs-structure

* [Docs] Check link and fix rst  (#498)

* check link

* fix rst

* Fix conf.py

* Fix lint

* minor refine

* minor refine

* modify zh_readme and index.rst

* add migration exampls get_started design to en

* add tutorials to en

* correct chinese doc link

* Apply suggestions from code review

* Update docs/en/advanced_tutorials/distributed.md

Co-authored-by: Zaida Zhou <58739961+zhouzaida@users.noreply.github.com>

Co-authored-by: Mashiro <57566630+HAOCHENYE@users.noreply.github.com>

* fix unit test install mmdet and mmcls

* raise error when mmdet is not installed

* rename check_and_install to install_package

* split test case

Co-authored-by: C1rN09 <zhaoqian@pjlab.org.cn>

* Add README.md

* add introduction

* resolve comments

* final refinement

* structure tutorials

* refine data element docs

* modify introduce

* fix comment

* fix comment

* fix comment

* migrate model

* fix title error

* refine as comment

* fix as comment

* minor refine

* Fix as comment

* Update docs/zh_cn/migration/migrate_model_from_mmcv.md

* Update docs/zh_cn/migration/migrate_model_from_mmcv.md

Co-authored-by: Qian Zhao <112053249+C1rN09@users.noreply.github.com>

* [Fix] fix the typo

* [Fix] add the missing argument

* add an example for gan training

* remove data element

* fix as comments

* add type_as

* fix as comment

* refine

* fix as comment

* add more descriptions

* fix as comment

* fix a api

* Add the distributed training script

* fix md format

* tmp commit

* refine docstring

* minor refine

* fix as comment

* add tutorial for merge_from_dict

* minor refine

* minor refine

* export md by jupyter

* temp add ipnb

* refine the docs

* remote ipynb

* fix as comment

* add change _base_.variable

* Fix as comment

* minor refine

* Fix as comment

* Fix as comment

* minor refine

* first commit

* tmp commit

* tmp commit

* tmp

* finish base module

* tmp commit

* tmp commit

* first finish

* minor refine

* clean the code

* delete design

* refine

* minor refine

* fix as comment

* fix as comment

* refine from jupyter notebook

* minor refine

* split model.md to model.md and initialize.md

* minor refine

* minor refine

* make link availiable

* fix as chengqi comment

* fix as chengqi comment

* fix link

* fix as wenwei comment

* Fix as comment

* Fix as comment

* Fix lint

* [Docs] Add data transform tutorials

* Rename `RandomMultiscaleResize` to `RandomChocieResize`.

* Imporve according to comments

* Add general data pipeline description.

* [Docs] Make API of docs clearer

* minor fix

* fix md format