* rebase
* update process
* add TODOs in moved classes
* update APIs
* modify the preprocess_cfg to data_preprocessor
* Fix api docs.
Co-authored-by: mzr1996 <mzr1996@163.com>
* [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