Remove the `markdownify` call, and instead rely on Hugo's proper syntax; `{{% callout %}}` when we want to the content to be processed as Markdown.
This allows for stuff like:
{{% callout info %}}
##### I'm an info callout!
```css
.foo {
color: #fff;
}
```
{{< example >}}
<div class="alert alert-warning alert-dismissible fade show" role="alert">
<strong>Holy guacamole!</strong> You should check in on some of those fields below.
<button type="button" class="btn-close" data-dismiss="alert" aria-label="Close"></button>
</div>
{{< /example >}}
{{% /callout %}}
* Expand on disabled fieldsets and faked buttons
include further advice/information on how to disable faked buttons for keyboard/AT users
* Centralise accessible name advice in forms overview
seems odd to only mention (separately) label, aria-label etc in input-group and layout. the advice is just as pertinent in other sections like select. checks only skims over this.
moving this, in expanded form, into the overview section itself. adding a specific cross-reference (just because they are easily left with no accname at all) in the checks page.
* Change warning about accessibility, modify server-side example
- paradoxically, due to our current problems with validation (see #28414) and the fact that browsers seem to have improved in this area for the most part, it's now actually better to use browser-native validation
- added explicit `id` and `aria-describedby` association to at least the server-side form error messages, to show how it should be done properly, and expanded the prose for that explaining this.
* Replace `.sr-only` with `.visually-hidden` in new addition
* Copy edits for clarity in parenthetical
* Copy and formatting tweaks
- Wordsmithing here and there
- Turns some hyphens into em dashes
- Turns a long running comma separated list into an unordered list
- Rearranges some copy just a bit
Co-authored-by: Mark Otto <markd.otto@gmail.com>
