Repository: Qiskit/qiskit

Issue:
multi-language documentation 
<!-- ⚠️ If you do not respect this template, your issue will be closed -->
<!-- ⚠️ Make sure to browse the opened and closed issues to confirm this idea does not exist. -->

### What is the expected behavior?
I would like to remove all the multi-language documentation from this repository and add it to github.com/Qiskit/qiskit. I am not sure of the best way we do it and I let all discuss in that repository how we should do it. But we are not going to have documentation in the individual elements (only a readme about the element, contributing guidelines and other community files)

@alfrisch could you take the lead on the German
@rraymondhp could you take the lead on the Japanese
@hanheepaik could you take the lead on the Korean
@liupibm could you take the lead on the Chinese

Thanks 





Discussion:
Discussed @diego-plan9 and @veenaiyuri a plan to test a doc directory structure to include translated content by adding a new directory level, `/nl/` Translated docs can be included as comprehensive doc packages as subdirectories, for example `/nl/ja/filename` for Japanese translations of a specific `filename`.  For example:

```
docs
|--images
|--
|--nl
   |--de
   |--ja
   |--ko
   |--zh
```

This directory structure sounds good! For collaboration via git it is important to work on the translation on a file-by-file basis.
As long as we do not have this structure up and running, I think it would be better to link German and Japanese to the English doc by default as these versions are quite old and this might give a wrong impression.
Hitting a language button when there is no translated file I get a "not found" error. Maybe it is better to hide the link when no corresponding translation is present.
About the japanese translation, we do agree, but the naming of root directory `nl` may need reconsideration as it looks like the name of a particular language (netherland?). Will issue a PR about it soon. 
You are right. 'nl' does stand for Netherlands. How about 'lang' instead?
 ```
docs
|--images
|--
|--lang
   |--de
   |--ja
   |--ko
   |--zh
```

Resolving patch:
diff --git a/docs/de/conf.py b/docs/de/conf.py
deleted file mode 100644
--- a/docs/de/conf.py
+++ /dev/null
@@ -1,20 +0,0 @@
-#!/usr/bin/env python3
-# -*- coding: utf-8 -*-
-"""
-Language specific configuration file, inheriting from the main /doc
-conf.py file and adjusting the variables that depend on the language.
-"""
-
-import os
-import sys
-
-sys.path.insert(0, os.path.abspath('..'))
-from conf import *
-
-language = 'de'
-exclude_patterns = ['_build', 'Thumbs.db', '.DS_Store', '_autodoc/modules.rst']
-
-templates_path = ['../_templates']
-html_static_path = ['../theme/static/']
-html_logo = '../theme/static/qiskit-logo-white-no-margin.gif'
-html_favicon = '../theme/static/favicon.ico'
diff --git a/docs/ja/conf.py b/docs/ja/conf.py
deleted file mode 100644
--- a/docs/ja/conf.py
+++ /dev/null
@@ -1,20 +0,0 @@
-#!/usr/bin/env python3
-# -*- coding: utf-8 -*-
-"""
-Language specific configuration file, inheriting from the main /doc
-conf.py file and adjusting the variables that depend on the language.
-"""
-
-import os
-import sys
-
-sys.path.insert(0, os.path.abspath('..'))
-from conf import *
-
-language = 'ja'
-exclude_patterns = ['_build', 'Thumbs.db', '.DS_Store', '_autodoc/modules.rst']
-
-templates_path = ['../_templates']
-html_static_path = ['../theme/static/']
-html_logo = '../theme/static/qiskit-logo-white-no-margin.gif'
-html_favicon = '../theme/static/favicon.ico'


Test patch: