* add faster rcnn C5

* add trained faster rcnn C5 model url

* fix typos

* update based on 1-st comments

* update unittest for ChannelMapper

* small changes of ChannelMapper's docstring

* small changes of ChannelMapper's docstring

* [Enhancement] Refactor Q&A

* fix typo

* fix cudatoolkit

* rename

* resovle cmts

* reanme

* fixed yaml

* add link

* bump to v2.6.0

* update version requirements

* Add README.md reference

* Fix README.md

Refactor documentation

* add rpn upgrade scripts for v2.5.0 compatibility

* rephrase docs

[Doc] Refactor doc on `tools/`

* add varifocal loss, vfnet head and config file

* fix nonzero() and register_module bug

* add more configs and README.md

* enlarge image in README.md

* add arxiv link

* add paper arxiv link

* attempt to fix checks error - res2net

* update readme

* update according to comments

* revert res2net.py

* compact the VFNetHead

* adapt for official TTA

* add unit tests and refine vfnet_head

* update url

* update readme

* add minor comments

* update supported models

* remove VFNet.png

Co-authored-by: Cao Yuhang <yhcao6@gmail.com>

Add docs

* Use mmdet.apis

* Add show_dir and show_score_thr args

* pre-commit

* Save each corruption in separate folder

* Save each corruption in separate folder

* speed up and improve stabe paa

* fix yapf

* change default value of covariance_type

* change precisions_init

* Add tied covariance type

* Change default covariance_type

Co-authored-by: d.rybalchenko <d.rybalchenko@visionlabs.ru>
Co-authored-by: rydenisbak <rydenisbak@mail.ru>

* ga ret r50 model url update

* update url

Tutorial refactor data train

* [enhance]: RoIAlign in mmcv is supported with aligned=False in CPU mode

* [Fix]: RoIPool doesn't have `aligned` attribute

* [enhance]: CPU inference with RoIPool is not supported currently (#3930)

Add supports for giou calculation in BboxOverlaps2D, and re-implements giou_loss using bbox_overlaps (#3936)

* supports for BboxGIoU2D and re-implements giou_loss using bbox_gious

* remove unnecessary

* reformat

* reformat docstring

* reformat

* rename

* supports for giou calculating in BboxOverlaps2D, and re-implements giou_loss using bbox_overlaps

* reformat

* move giou related unit test from test_losses.py to test_iou2d_calculator.py

* reformat

* Avoid division by zero in PAA head when num_pos=0

* explicitly add mode in giou_loss

[doc] tutorial for existing dataset and model