Add .profvis-code scope to CSS

[wch]

This makes it so that profvis will not affect other blocks of code, such as those from rmarkdown or Quarto.

Note: this still needs to be tested.

Fixes #140

[hadley]

This doesn't appear to work — now the code has no syntax highlighting. Probably because we also need to adjust the scope that highlight.js is applied to.

[hadley]

Looks like we need to update highlight.js and then call hljs.highlightElement(element) with the appropriate element.

[hadley]

Actually, we're already doing that:

      rows.append("td")
        .attr("class", "code r")
        .text(function(d) { return d.content; })
        .each(function() { hljs.highlightBlock(this); });

So it might be sufficient to update highlight.js?

[hadley]

This is definitely an improvement since we the styles are now better scoped, but it still appears to be re-styling other code blocks, and I can't figure out why.

[hadley]

Updating highlight to latest version to fixes the problem, since it no longer automatically highlights pre blocks across the whole page.

[hadley]

@wch do you mind double checking with this reprex?

---
format: html
---

```{r}
f <- function() {
  pause(0.1)
}
profvis::profvis(f())
```

```r
f <- function() {
  pause(0.1)
}
profvis::profvis(f())
```

[wch]

This is with a slightly different version, with the code inside the profvis() call, so that we can see the code in the profvis panel as well.

---
format: html
---


```{r}
profvis::profvis({
  f <- function() {
    pause(0.1)
  }
  
  f()
})
```


```r
profvis::profvis({
  f <- function() {
    pause(0.1)
  }
  
  f()
})
```

[hadley]

Good idea. That all looks good to me.