GitLab

* [doc] fix title of mixed precision

* [doc]update document of zero with chunk

* [doc] update document of zero with chunk, fix

* [doc] update document of zero with chunk, fix

* [doc] update document of zero with chunk, fix

* [doc] update document of zero with chunk, add doc test

* [doc] update document of zero with chunk, add doc test

* [doc] update document of zero with chunk, fix installation

* [doc] update document of zero with chunk, fix zero with chunk doc

* [doc] update document of zero with chunk, fix zero with chunk doc

* fix typo colossalai/autochunk auto_parallel amp

* fix typo colossalai/auto_parallel nn utils etc.

* fix typo colossalai/auto_parallel autochunk fx/passes  etc.

* fix typo docs/

* change placememt_policy to placement_policy in docs/ and examples/

* [doc] added reference to related works

* polish code