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

Aster Hu

2024-02-22 916aedce40864a485724d9df78879e8d130beab3

 quartz/components/styles/footer.scss

@@ -1,6 +1,8 @@
footer {
  text-align: left;
  opacity: 0.8;
  margin-bottom: 4rem;
  opacity: 0.7;

  & ul {
    list-style: none;
    margin: 0;