img in horizontal card (twbs#34160)

* docs(cards): img in horizontal card

Closes twbs#34145 

Simply adds `img-fluid` and `rounded-start` classes to horizontal card example to ensure copy-pasting from the docs matches the expectation.

* Update site/content/docs/5.0/components/card.md

Co-authored-by: Mark Otto <markd.otto@gmail.com>

site/content/docs/5.0/components/card.md

@@ -398,7 +398,7 @@ Using a combination of grid and utility classes, cards can be made horizontal in
 <div class="card mb-3" style="max-width: 540px;">
  <div class="row g-0">
  <div class="col-md-4">
-  {{< placeholder width="100%" height="250" text="Image" >}}
+  {{< placeholder width="100%" height="250" text="Image" class="img-fluid rounded-start" >}}
  </div>
  <div class="col-md-8">
   <div class="card-body">