docs: Add Aster's notebook to showcase.md (#912)

Aster Hu

2024-02-22 916aedce40864a485724d9df78879e8d130beab3

 quartz/plugins/transformers/gfm.ts

@@ -32,6 +32,7 @@
            {
              behavior: "append",
              properties: {
                role: "anchor",
                ariaHidden: true,
                tabIndex: -1,
                "data-no-popover": true,