Given this content:
```bash
archetypes
├── default.md
└── post-bundle
├── bio.md
├── images
│ └── featured.jpg
└── index.md
```
```bash
hugo new --kind post-bundle post/my-post
```
Will create a new folder in `/content/post/my-post` with the same set of files as in the `post-bundle` archetypes folder.
This commit also improves the archetype language detection, so, if you use template code in your content files, the `.Site` you get is for the correct language. This also means that it is now possible to translate strings defined in the `i18n` bundles, e.g. `{{ i18n "hello" }}`.
Fixes#4535