[Docs] Remove the _static in docs_zh_CN (#1277)

* [Docs] Remove _static in docs_zh_CN

* fix html_static_path

* fix shpinx warning

docs/community.rst

@@ -5,3 +5,4 @@ Community
    :maxdepth: 2
 
    community/contributing.md
+   community/pr.md

docs_zh_CN/_static

-../docs/_static
\ No newline at end of file

docs_zh_CN/community.rst

@@ -5,3 +5,4 @@
    :maxdepth: 2
 
    community/contributing.md
+   community/pr.md

docs_zh_CN/community/pr.md

@@ -20,7 +20,7 @@
 1. 获取最新的代码库
     + 当你第一次提 PR 时
         - 复刻 OpenMMLab 原代码库，点击 GitHub 页面右上角的 **Fork** 按钮即可
-        ![avatar](../_static/community/1.png)
+        ![avatar](../../docs/_static/community/1.png)
 
         - 克隆复刻的代码库到本地
             ```bash
@@ -58,13 +58,13 @@
         ```
 
     + 创建一个`拉取请求`
-    ![avatar](../_static/community/2.png)
+    ![avatar](../../docs/_static/community/2.png)
 
     + 修改`拉取请求`信息模板，描述修改原因和修改内容。还可以在 PR 描述中，手动关联到相关的`议题` (issue),（更多细节，请参考[官方文档](https://docs.github.com/en/issues/tracking-your-work-with-issues/linking-a-pull-request-to-an-issue)）。
 
 5. 讨论并评审你的代码
     + 创建`拉取请求`时，可以关联给相关人员进行评审
-    ![avatar](../_static/community/3.png)
+    ![avatar](../../docs/_static/community/3.png)
 
     + 根据评审人员的意见修改代码，并推送修改
 

docs_zh_CN/conf.py

@@ -102,7 +102,7 @@ html_theme = 'sphinx_rtd_theme'
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
-html_static_path = ['_static']
+html_static_path = ['../docs/_static']
 
 # Custom sidebar templates, must be a dictionary that maps document names
 # to template names.

docs_zh_CN/understand_mmcv/data_process.md

@@ -252,7 +252,7 @@ flow = mmcv.flowread('compressed.jpg', quantize=True, concat_axis=1)
 mmcv.flowshow(flow)
 ```
 
-![progress](../_static/flow_visualization.png)
+![progress](../../docs/_static/flow_visualization.png)
 
 3. 流变换
 
@@ -264,12 +264,12 @@ warpped_img2 = mmcv.flow_warp(img1, flow)
 
 img1 (左) and img2 (右)
 
-![raw images](../_static/flow_raw_images.png)
+![raw images](../../docs/_static/flow_raw_images.png)
 
 光流 (img2 -> img1)
 
-![optical flow](../_static/flow_img2toimg1.png)
+![optical flow](../../docs/_static/flow_img2toimg1.png)
 
 变换后的图像和真实图像的差异
 
-![warpped image](../_static/flow_warp_diff.png)
+![warpped image](../../docs/_static/flow_warp_diff.png)