## Motivation
Translate Chinese version customized runtime doc into English
https://github.com/open-mmlab/mmsegmentation/pull/2502.

* [WIP] Refine documentation

* get started done

* config refine

* train_test

* refine user guides

* add contribution

* add contribution

* refine visualization

* advanced tutorial

* advanced guides

* tricks

* refine zh doc

* refactor changelog

* [Doc] MMSeg 1.x Documentation

* revise index

* merge docs/ and docs_zh-CN/

* merge docs/ and docs_zh-CN/

* merge docs/ and docs_zh-CN/

* merge docs/ and docs_zh-CN/

* fix launch utility url

* fix launch utility url

* fix wrong pytorch doc url

* remove wrong links docs//

* add codespell pre-commit hook and fix typos

* Update mmseg/models/decode_heads/dpt_head.py

* Update mmseg/models/backbones/vit.py

* Update mmseg/models/backbones/vit.py

* fix typos

* skip formating typo

* deprecate formating

* skip ipynb

* unstage ipynb changes

* unstage ipynb changes

* fix typos in ipynb

* unstage ipynb changes

* Improve docs style

* update lists

* update the size of image

* modify duplicate mmdet3d

* refactor docs

* add docs

* add modelzoo

* refactor getting started