[i18n] Content: Always enforce lang code in filename


Id like to be forced to always have to use the language code for any page or section despite having a default language enabled. The problem is, when you change the default language, your content becomes corrupt because it assumes your default language pages (those without a *.{code}.md) to be written in this language. The current behaviour strictly expects default language pages to have no {code} at all for pages and sections. At least Id like to be able to add the language {code} to all pages and expect the checker to be smart enough to be satisfied with having all pages translated in the default language. The default language feature should only be meaningful for routes.

See doc: https://www.getzola.org/documentation/content/multilingual/#content

Thank you alot