use lowercase

Author: cderv

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

@@ -492,7 +492,7 @@
   description: >
     Embed [Nutshell](https://ncase.me/nutshell/) expandable explanations in HTML documents.
 
-- name: Offcanvas
+- name: offcanvas
   path: https://github.com/mcanouil/quarto-offcanvas
   author: '[Mickaël CANOUIL](https://github.com/mcanouil)'
   description: >