i18n Foundation and adding Japanese pages

[yuhattor]

@voborgus @InnerSourceCommons/website-maintainers
I have created a Japanese page on innersourcecommons.org, and there is a staging site at innersourcecommons.jp.
Please check and merge it:)

Now that we have this foundation in place, the next step may be to translate the materials into German, Russian, etc. I will create branches and make a base in the future to try it out after this PR is successfully merged.

There are still some issues with integration with Learning Path: all Learning Path materials now reside under content/en/, and they are moved correctly when gh-pages are created, so it doesn't essentially affect functionality. It's not pretty though, so I'll fix that in the future.

For more info, please check the issue #355

[yuhattor]

Except for heroku slack inviter and some original broken pages, linkcheck has already succeeded. No Japanese-specific problems exist.

[voborgus]

Million thanks for the huge work you're doing!

Some comments before the merge:

Looks like the last item in the menu still untranslated.

Also noticed a bug (imho can leave for now but then to not to forget to do smth):

• Go to learning path.
• Change language to German (or other except en and ja).
• Go to home page.

Language parameter continue to be German, but content is rsynced from English. If we change the language again, German option will be hidden. This was handled correctly previously when there are no pages was autogenerated from english but now we may consider another behaviour. I'm expect to live a long time without translation to all languages :)

[voborgus]

Обучение

[voborgus]

Программа обучения

[voborgus]

Паттерны

[voborgus]

Каталог услуг

[voborgus]

Контакты

[voborgus]

Обучение

[voborgus]

Каталог услуг

[voborgus]

Участники

[voborgus]

Контакты

[yuhattor]

@voborgus
This is a matter for debate. Actually, this move is done this way by design

It would be very stressful if, when viewing a German page, the user had to leave that locale every time they went to an untranslated page. The user would be taken unawares to an untranslated page, but if they were taken to a /en (Default) page, they would have to revert to their own language each time.

In many cases, for example in the case of Microsoft documentation, there are each types of pages available, even if they are not translated, as follows
https://azure.microsoft.com/ja-jp/updates/public-preview-v2-programming-model-for-azure-functions-using-python/
https://azure.microsoft.com/en-us/updates/public-preview-v2-programming-model-for-azure-functions-using-python/

So far, there are 27 markdown files under content/ja, since there are 100+ markdown files under content/en. And since rsync is supposed to skip files that exist, there is no need to translate all pages or even add them to the codebase.
Let's say someone wants to translate only a minimum of 10 .md files, including the top page, in a new language, he/she doesn't have to translate the whole thing.

wdyt?

[voborgus]

You right, let's leave it for now – then we may decide other behaviour based on users feedback.

So small translation fixes left and ready to merge 👍🏻

[yuhattor]

@voborgus Could you merge it now?!
I fixed the small menu mistranslation in Russian and all checks have passed:)

[yuhattor]

Again, the staging page is live now
https://innersourcecommons.jp/ru/learn/learning-path/

[voborgus]

Thanks! Lets merge it

[yuhattor]

Amazing!!!