Initialize adding the Simplified Chinese (zh-CN) translation of the fpm documents

[zoziha]

• add the Chinese translation.

CN Pages: https://zoziha.github.io/fpm-docs/cn/ (outdated)

[awvwgk]

I think cn is not matching any language sphinx-intl is aware of, however it has two entries for Chinese (see https://www.sphinx-doc.org/en/master/usage/configuration.html#options-for-internationalization):

• zh_CN – Simplified Chinese
• zh_TW – Traditional Chinese

Using either of those would also use translations for the blog and table of contents. If you prefer cn as path for the URL I can have a look how we can keep this path and still get the right translation from the sphinx-intl for the theme.

[zoziha]

Thanks, I'll replace cn with zh_CN.

[awvwgk]

Thanks a lot, I'll go ahead and merge.