* init npu

* Update mmengine/optim/optimizer/amp_optimizer_wrapper.py

Co-authored-by: Zaida Zhou <58739961+zhouzaida@users.noreply.github.com>

* Update mmengine/dist/dist.py

Co-authored-by: Zaida Zhou <58739961+zhouzaida@users.noreply.github.com>

* change to is_hccl_backend

* Update mmengine/optim/optimizer/amp_optimizer_wrapper.py

Co-authored-by: Zaida Zhou <58739961+zhouzaida@users.noreply.github.com>

* add comment with AmpOptimWrapper

* Update mmengine/runner/amp.py

Co-authored-by: Zaida Zhou <58739961+zhouzaida@users.noreply.github.com>

* Update mmengine/runner/amp.py

Co-authored-by: Zaida Zhou <58739961+zhouzaida@users.noreply.github.com>

* add npu fn in base_model

* Update mmengine/optim/optimizer/amp_optimizer_wrapper.py

Co-authored-by: Zaida Zhou <58739961+zhouzaida@users.noreply.github.com>

* clean lint

* Update mmengine/optim/optimizer/amp_optimizer_wrapper.py

Co-authored-by: Zaida Zhou <58739961+zhouzaida@users.noreply.github.com>

* Update mmengine/model/base_model/base_model.py

Co-authored-by: Mashiro <57566630+HAOCHENYE@users.noreply.github.com>

* add is_npu_available

* try to fix

* Add comments

* Refine grammar

Co-authored-by: Zaida Zhou <58739961+zhouzaida@users.noreply.github.com>
Co-authored-by: Mashiro <57566630+HAOCHENYE@users.noreply.github.com>
Co-authored-by: HAOCHENYE <21724054@zju.edu.cn>

* [Docs] Fix api files of en docs

* minor fix

* [Docs] Make API of docs clearer

* minor fix

* fix md format