* Move the design of hook to design/hook.md

* add relative links in docs

* update docstring of hooks

* refine checkpointhook docs

* refine

* fix comments

* refine

* add logging.md link in hook.md

* resolve comments

* fix typo

* [Docs] Add speed training examples

* refine

* refine

* rename filename

* minor refine

* modify the tutorials of basedataset

* tmp commit

* Add save_gpu_memory docs

* update

* fix comment

* fix comment

[Visualizer] use FigureManager to manage figure to avoid affecting plt.show() outside Visualizer(#440)

* figure in Visualizer is not managed by plt

* encapsulate code and remove unused code

* [Doc] Update runner documents.

* update

* fix link

* update

* update

* Update import manner of Runner

Co-authored-by: Wenwei Zhang <40779233+ZwwWayne@users.noreply.github.com>

* docs: modify distributed tutorials

* docs: modify distributed tutorials

* docs(zh_cn/tutorials): fix wrong modifications in distributed.md

[Refactor]: migrate LMDB backends and modifications from open-mmlab/mmcv#1764 and  open-mmlab/mmcv#1747 (#426)

* Add fileio ut

* pick modification from master branch

* pick modification from mmcv #1764

* test fileio without mmcv

* remove unnecessary checking

* [Docs] Update scheduler doc.

* update

* Support build evaluator from list of built metric

* regist evaluator

* fix as comment

* add unit test

* Add installation docs

* fix typo

* support build optimizer wrapper from built Optimizer instance

* refine comments

* make default scope of runner be mmengine

* fix as comment

* Makr logger compatible with python3.6

* minor refine

* fix as comment

* [Enhancement] Add unit test for get_priority

* fix priority ut

* fix typo

Co-authored-by: Wenwei Zhang <40779233+ZwwWayne@users.noreply.github.com>

* [Feature] Support CosineRestartParamScheduler.

* add ut and docstring

* add docstring

* fix wrong epoch andd iter when save bbest ckpt

* fix ut

* fix resume best ckpt unexpectedly

* minor refine

* fix unit test

* support training with data without metainfo

* clean the code

* clean the code

* [Enhance] Add `preprocess_cfg` as an argument of runner.

* Rename `preprocess_cfg` to `data_preprocessor`

* Fix docstring

* Support log enviroment information when initiate runner

* Fix unit test

* fix as comment, save world_size

* log gpu num

* clear code and reformat log

* minor refine

* fix as comment

* minor refine

* clean the code

* clean the code

* remove save world_size in meta

* add build function for scheduler

* add unit test

add unit test

* handle convert_to_iter in build_scheduler_from_cfg

* restore deleted code

* format import

* fix lint

* BaseAveragedModel support load ckpt without module prefix

* refine docstring

* allow EMAHook does not load ckpt strictly

* add unit test for strict argument of EMAHook

* sync remote

* sync remote

* clean the code

* ema hook supports setting start iter

* fix unit test

* fix as comment

* fix as comment

* describe kwargs

* support save best based on multi metrics

* add unit test

* resolve bugs after rebasing

* revise docstring

* revise docstring

* fix as comment

* revise as comment

* Support changing value of dict in config(without base config)

* minor refine