Translation files hierarchy and Crowdin project setup

Hello human intelligences :)

As explained [here](https://github.com/dair-ai/Prompt-Engineering-Guide/issues/75#issuecomment-1512900823), I started setting up a Crowdin project to translate the project and stumbled on configuring Nextra's [i18n file naming pattern](https://nextra.site/docs/guide/i18n#use-add-locale-to-filenames) for translated files (see my message [here](https://community.crowdin.com/t/files-path-configuration-for-a-nextra-site-with-github-integration/3894)).

If as suggested by @omarsar, translated files could live in their own tree, and we could get rid of the `.en` in English source file names, that would make this configuration a piece of cake. It would also ease the import of existing translations in Crowdin, in addition to automating the creation of new languages for translators as well as the translation update workflow.

Thus, I'm proposing to use a `locales` or `lang` directory at the root of the repository, holding a two letter language code named folders for each translation. In each of these, the hierarchy of the translated files would follow the one of the English sources.
I.e., for French, that'd be `lang/fr/[pages|guides]/`.

Hope you'll like that proposal
TY
J

Edit: Actually, the real pain point is the `.en` in English source file names, as configuration would be as easy with a 'merged hierarchy'