Cannot use the new structure of .devcontainer directory

The new standard in DevContainer allow to have several files `devcontainer.json` in subdirectories of `.devcontainer` directory.

The arguments `--name` and `--path` cannot be used.

For example:
```
.
├── .devcontainer
│   ├── context1
│   │   └── devcontainer.json
│   └── context2
│       └── devcontainer.json
```
