[Docs]: Add ops definition (#1434)

* [Improve] improve checkpoint loading log (#1446)

* add first version

* remove syncbn

* remove unused ops

* update input names

* remove empty line

* update index.rst

* resolve comments

* fix type

* Update mmcv_ops_definition.md
Co-authored-by: WangJiaZhen <47851024+teamwong111@users.noreply.github.com>
Co-authored-by: maningsheng <mnsheng@yeah.net>
Co-authored-by: Zaida Zhou <58739961+zhouzaida@users.noreply.github.com>

docs/index.rst

@@ -34,6 +34,7 @@ You can switch between Chinese and English documents in the lower-left corner of
    deployment/onnxruntime_custom_ops.md
    deployment/tensorrt_plugin.md
    deployment/tensorrt_custom_ops.md
+   deployment/mmcv_ops_definition.md
 
 .. toctree::
    :maxdepth: 2