Add quarto-quiz into RevealJS extensions list (#1262)

Author: parmsam

Diff for: docs/extensions/listings/revealjs.yml

@@ -127,3 +127,9 @@
   author: "[Sam Parmar](https://github.com/parmsam)"
   description: |
     Adds live webcam video feed to slides.
+
+- name: quiz
+  path: https://github.com/parmsam/quarto-quiz
+  author: "[Sam Parmar](https://github.com/parmsam)"
+  description: |
+    Adds multiple choice quiz questions to slides.