move docs under en_US (#744)

* move en docs under en_US

* update gitignore

* fix image link

* add doc guide

* add napoleon ext

docs/PAIMode.md → docs/en_US/PAIMode.md

@@ -62,17 +62,17 @@ nnictl create --config exp_pai.yml
 ```
 to start the experiment in pai mode. NNI will create OpenPAI job for each trial, and the job name format is something like `nni_exp_{experiment_id}_trial_{trial_id}`. 
 You can see jobs created by NNI in the OpenPAI cluster's web portal, like:
-![](./img/nni_pai_joblist.jpg)
+![](../img/nni_pai_joblist.jpg)
 
 Notice: In pai mode, NNIManager will start a rest server and listen on a port which is your NNI WebUI's port plus 1. For example, if your WebUI port is `8080`, the rest server will listen on `8081`, to receive metrics from trial job running in Kubernetes. So you should `enable 8081` TCP port in your firewall rule to allow incoming traffic. 
 
 Once a trial job is completed, you can goto NNI WebUI's overview page (like http://localhost:8080/oview) to check trial's information. 
 
 Expand a trial information in trial list view, click the logPath link like:
-![](./img/nni_webui_joblist.jpg)
+![](../img/nni_webui_joblist.jpg)
 
 And you will be redirected to HDFS web portal to browse the output files of that trial in HDFS:
-![](./img/nni_trial_hdfs_output.jpg)
+![](../img/nni_trial_hdfs_output.jpg)
 
 You can see there're three fils in output folder: stderr, stdout, and trial.log
 

docs/QuickStart.md → docs/en_US/QuickStart.md

@@ -183,28 +183,28 @@ Click the tab "Overview".
 
 Information about this experiment will be shown in the WebUI, including the experiment trial profile and search space message. NNI also support `download these information and parameters` through the **Download** button. You can download the experiment result anytime in the middle for the running or at the end of the execution, etc.
 
-![](./img/QuickStart1.png)
+![](../img/QuickStart1.png)
 
 Top 10 trials will be listed in the Overview page, you can browse all the trials in "Trials Detail" page.
 
-![](./img/QuickStart2.png)
+![](../img/QuickStart2.png)
 
 #### View trials detail page
 
 Click the tab "Default Metric" to see the point graph of all trials. Hover to see its specific default metric and search space message.
 
-![](./img/QuickStart3.png)
+![](../img/QuickStart3.png)
 
 Click the tab "Hyper Parameter" to see the parallel graph.
 
 * You can select the percentage to see top trials.
 * Choose two axis to swap its positions
 
-![](./img/QuickStart4.png)
+![](../img/QuickStart4.png)
 
 Click the tab "Trial Duration" to see the bar graph.
 
-![](./img/QuickStart5.png)
+![](../img/QuickStart5.png)
 
 Below is the status of the all trials. Specifically:
 
@@ -213,11 +213,11 @@ Below is the status of the all trials. Specifically:
 * Kill: you can kill a job that status is running.
 * Support to search for a specific trial.
 
-![](./img/QuickStart6.png)
+![](../img/QuickStart6.png)
 
 * Intermediate Result Grap
 
-![](./img/QuickStart7.png)
+![](../img/QuickStart7.png)
 
 ## Related Topic
 

docs/SQuAD_evolution_examples.md → docs/en_US/SQuAD_evolution_examples.md

@@ -13,7 +13,7 @@ We conclude the search space as follow:
 6. ADD-SKIP (Identity between random layers).
 7. REMOVE-SKIP (Removes random skip).
 
-![](https://github.com/Microsoft/nni/tree/master/examples/trials/ga_squad/ga_squad.png)
+![](../../examples/trials/ga_squad/ga_squad.png)
 
 ### New version
 Also we have another version which time cost is less and performance is better. We will release soon.

docs/WebUI.md → docs/en_US/WebUI.md

@@ -7,16 +7,16 @@ Click the tab "Overview".
 * See the experiment trial profile and search space message.
 * Support to download the experiment result.
 
-![](./img/webui-img/over1.png)
+![](../img/webui-img/over1.png)
 * See good performance trials.
 
-![](./img/webui-img/over2.png)
+![](../img/webui-img/over2.png)
 
 ## View job default metric
 
 Click the tab "Default Metric" to see the point graph of all trials. Hover to see its specific default metric and search space message.
 
-![](./img/accuracy.png)
+![](../img/accuracy.png)
 
 ## View hyper parameter
 
@@ -25,13 +25,13 @@ Click the tab "Hyper Parameter" to see the parallel graph.
 * You can select the percentage to see top trials.
 * Choose two axis to swap its positions
 
-![](./img/hyperPara.png)
+![](../img/hyperPara.png)
 
 ## View Trial Duration
 
 Click the tab "Trial Duration" to see the bar graph.
 
-![](./img/trial_duration.png)
+![](../img/trial_duration.png)
 
 ## View trials status 
 
@@ -39,15 +39,15 @@ Click the tab "Trials Detail" to see the status of the all trials. Specifically:
 
 * Trial detail: trial's id, trial's duration, start time, end time, status, accuracy and search space file.
 
-![](./img/webui-img/detail-local.png)
+![](../img/webui-img/detail-local.png)
 
 * If you run on OpenPAI or Kubeflow platform, you can also see the hdfsLog.
 
-![](./img/webui-img/detail-pai.png)
+![](../img/webui-img/detail-pai.png)
 
 
 * Kill: you can kill a job that status is running.
 * Support to search for a specific trial.
 * Intermediate Result Graph.
 
-![](./img/intermediate.png)
+![](../img/intermediate.png)

docs/assessors.rst → docs/en_US/assessors.rst

@@ -8,7 +8,7 @@ Here is an experimental result of MNIST after using 'Curvefitting' Assessor in '
 
 *Implemented code directory: config_assessor.yml <https://github.com/Microsoft/nni/blob/master/examples/trials/mnist/config_assessor.yml>*
 
-..  image:: ./img/Assessor.png
+..  image:: ../img/Assessor.png
 
 Like Tuners, users can either use built-in Assessors, or customize an Assessor on their own. Please refer to the following tutorials for detail:
 

docs/conf.py → docs/en_US/conf.py

@@ -44,6 +44,7 @@ extensions = [
     'sphinx.ext.mathjax',
     'sphinx_markdown_tables',
     'sphinxarg.ext',
+    'sphinx.ext.napoleon',
 ]
 
 # Add any paths that contain templates here, relative to this directory.
@@ -107,7 +108,7 @@ html_theme_options = {
 #
 # html_sidebars = {}
 
-html_logo = './img/nni_logo_dark.png'
+html_logo = '../img/nni_logo_dark.png'
 
 # -- Options for HTMLHelp output ---------------------------------------------