Accessibility issue on partial translation

[JohnXLivingston]

Hello,

I'm using po4a to translate markdown pages, then i'm using Hugo to generate a static website.

I have an accessibility issue for partial translations: Hugo adds a lang attribute on the page, and i can't change its value.

When the translation is incomplete (or completely empty) we have - for example - lang="it" on the webpage, but the content is in english.
This breaks screen readers (for blind people), as it tries to read english words as italian.

It would be nice to have an option to add <span lang="en"> for all non-translated strings in the markdown file.

Note: this solution will not work for the frontmatter, only for the markdown content. For the frontmatter i have no idea yet. But it would be a great start to have the span solution to begin.

[Fat-Zer]

I suppose, it shouldn't be too hard (famous last words) to add an option to provide some decorators for untranslated text.

Though, I'm a bit hesitant about the exact user-facing config syntax of all this. And unsure how meticulous we should be about filtering what strings the decorators should apply to.

@mquinson, your thoughts?