* [Docs] Make API of docs clearer * minor fix * fix md format
* Update demo in get started tutorial * Update demo tutorial * Refactor the pytorch demo * Add outline and titles to the demo tutorial. * Move file and change title * Add shuffle in dataloader arguments. * Improve according to comments
* add introduction of mmengine in get_started.md * resolve comments * resolve comments * resolve comments * resolve comments * resolve comments * resolve comments * update figs
* Add installation docs * fix typo