* [Refactor] Refactor the rest data transforms and fix some docstring.
* Use `mmengine` instead of `mmcv`
* Refactor KFold dataset tools
* Fix docstring according to comments
* [Refactor] Refactor the docs structure.
* Rename `getting_started.md` to `get_started.md`
* Rename `transforms` to `data_process`
* [Docs] The template provides united Docs and OpenMMLab drop-lists in
banner. Remove them from our `conf.py`.
* Move docs of different languages to the same folder