When the `lang` is specified under a format, like:

```
format:
  html:
    lang: zh
```

We don't respect that lang when rendering a book (it must instead be at the root level).

See #251
dragonstyle
2022-09-04T13:37:45Z
dragonstyle
v1.4
open
`lang` provided under `format` key not respected when rendering books
https://github.com/quarto-dev/quarto-cli/issues/2285