[Docs] Refactor the structure of documentation (open-mmlab#1128)

* 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//

Author: MengzhangLI

.github/workflows/build.yml

@@ -16,7 +16,6 @@ on:
       - 'docker/**'
       - 'tools/**'
       - 'docs/**'
-      - 'docs_zh-CN/**'
       - '**.md'
 
 concurrency:

.gitignore

@@ -64,7 +64,8 @@ instance/
 .scrapy
 
 # Sphinx documentation
-docs/_build/
+docs/en/_build/
+docs/zh_cn/_build/
 
 # PyBuilder
 target/

README.md

@@ -230,7 +230,7 @@
     "\n",
     "Datasets in MMSegmentation require image and semantic segmentation maps to be placed in folders with the same perfix. To support a new dataset, we may need to modify the original file structure. \n",
     "\n",
-    "In this tutorial, we give an example of converting the dataset. You may refer to [docs](https://github.com/open-mmlab/mmsegmentation/docs/tutorials/new_dataset.md) for details about dataset reorganization. \n",
+    "In this tutorial, we give an example of converting the dataset. You may refer to [docs](https://github.com/open-mmlab/mmsegmentation/docs/en/tutorials/new_dataset.md) for details about dataset reorganization. \n",
     "\n",
     "We use [Standord Background Dataset](http://dags.stanford.edu/projects/scenedataset.html) as an example. The dataset contains 715 images chosen from existing public datasets [LabelMe](http://labelme.csail.mit.edu), [MSRC](http://research.microsoft.com/en-us/projects/objectclassrecognition), [PASCAL VOC](http://pascallin.ecs.soton.ac.uk/challenges/VOC) and [Geometric Context](http://www.cs.illinois.edu/homes/dhoiem/). Images from these datasets are mainly outdoor scenes, each containing approximately 320-by-240 pixels. \n",
     "In this tutorial, we use the region annotations as labels. There are 8 classes in total, i.e. sky, tree, road, grass, water, building, mountain, and foreground object. "