preserve lang attribute in <pre> codeblocks

On PyPI, fenced code blocks from markdown are translated to HTML as

<pre>
...
</pre>

On GitHub, the HTML preserves the language attribute (if given),

<pre lang="python">
...
</pre>

This helps third-party applications, like my Purple Pi, to do fancy stuff. (In the case of Purple Pi to render LaTeX math.) I’d love to see this on PyPI, too.

[di]

I haven’t taken a look, but if it’s bringing cmarkgfm more inline with what GFM is actually doing, that sounds good to me.

If it changes the styles significantly, we’ll make the necessary changes here (and downstream on PyPI) once we update the pin.

[nschloe]

fair enough - I tried to validate the request that OP had - and confirmed that GitHub’s own rendering doesn’t preserve a lang attribute either.

I tried again and found, contrary to your results, that GitHub does preserve the lang attribute. For example, the README.md

```abc
lorem
```

produces lang="abc".

See here for a test repo.

(I might be slow to reply since I’m holidays right now.)