Update shortcodes-and-filters.yml

Add [github-corner](https://github.com/parmsam/quarto-github-corner/tree/main) into Quarto filter extensions listing

(cherry picked from commit af35523)

Author: parmsam

docs/extensions/listings/shortcodes-and-filters.yml

@@ -240,6 +240,12 @@
   description: >
     Use GitHub short references (commits, issues, discussions, and pull request) directly into your Quarto documents.
 
+- name: github-corner
+  path: https://github.com/parmsam/quarto-github-corner
+  author: '[Sam Parmar](https://github.com/parmsam)'
+  description: >
+    Add a Github Corner into your HTML document.
+
 - name: hide-comment
   path: https://github.com/shafayetShafee/hide-comment
   author: '[Shafayet Khan Shafee](https://github.com/shafayetShafee)'