* [Refactor] Use mdformat instead of markdownlint to format markdown.
* Update unavailiable api links in tutorials
* Update CONTRIBUTING.md
* Use mdformat==0.7.9 to support Python 3.6
* Add cosine cool down lr updater
* Use ema hook
* Update decay mult
* Update configs.
* Update T2T-ViT readme and format all readme
* Update swin readme
* Update tnt readme
* Add docstring for `CosineAnnealingCooldownLrUpdaterHook`.
* Update t2t readme and metafile
* Add model-pages
* Add shortname in configs
* Use link directly instead of `switch_language.md`
* Auto collapse model-zoo pages.
* Fix link in RegVGG
* Add link replace
* fix lint
* add mytrain.py for test
* test before layers
* test attr in layers
* test classifier
* delete mytrain.py
* add mobilenet_v3.yml
* fix ymal
* rename model_zoo.yml to model-index.yml
* replace imagenet with imagenet-1k
* add yml
* fix VGG
* minor fix
* add model zoo
* add bs and epoch
* revised according to comments
* revised according to comments
* revised according to comments
* resolve conflicts
add heads and config for multilabel tasks
* minor change
* remove evaluating mAP in head
* add baseline config
* add configs
* reserve only one config
* minor change
* fix minor bug
* minor change
* minor change
* add unittests and fix docstrings