Allow Voice Access to find clickable cards (#5857)

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## Why are these changes needed?

Fixes accessibility issue (34)

## Related issue number

#5634 

## Checks

- [ ] I've included any doc changes needed for
<https://microsoft.github.io/autogen/>. See
<https://github.com/microsoft/autogen/blob/main/CONTRIBUTING.md> to
build and test documentation locally.
- [ ] I've added tests (if relevant) corresponding to the changes
introduced in this PR.
- [ ] I've made sure all auto checks have passed.

Co-authored-by: Ryan Sweet <[email protected]>

Author: peterychang

python/packages/autogen-core/docs/src/_static/custom.css

@@ -123,12 +123,23 @@ html[data-theme="light"] .bd-header {
 
 /* Copy button */
 .bd-article .docutils .docutils .copybtn:focus-visible:after {
-  /* border: 10px outset var(--pst-color-primary); */
     display: block;
     opacity: 1;
     visibility: visible;
 }
 
+/* Allow voice access to find clickable cards */
+.sd-card a {
+  position: absolute;
+  top: 0;
+  left: 0;
+  right: 0;
+  bottom: 0;
+  z-index: 1;
+  text-decoration: none;
+  color: inherit;
+}
+
 /* Long autodoc module names wrap on prev/next links */
 /* TODO: Should we extend this to the entire site? */
 .prev-next-title {