GitLab

* Merge English and Chinese doc into the same folder

* Add logo image back

* Add logo image back

* fix version of sphinx

* fix switch

* add chinese doc

* update

* Refine docs and license

* Change order of install

* Clean unnecessary requirements

* Install mmdet manually in readthedocs

* delete mmdet install

* reformat docstring in code

* Refine docs

* Reformat

* fix format issue