feat: implement file explorer component (closes #201) (#452)

Ben Schlegel

2023-09-15 91f9ae2d71d5c28ba7d2182eed5a9f77da1fbe8d

 quartz/components/styles/toc.scss

@@ -42,7 +42,9 @@
    & > li > a {
      color: var(--dark);
      opacity: 0.35;
      transition: 0.5s ease opacity, 0.3s ease color;
      transition:
        0.5s ease opacity,
        0.3s ease color;
      &.in-view {
        opacity: 0.75;
      }