feat: multi-level sidebar

chore: support multiple search elements

chore: sidebar display toc on mobile view

chore: add hamburger menu to navbar on mobile

chore: add markdown link hook

for opening external link in new window

chore: add sidebar footer

- put search under params.type
- make navbar link aware of external link

assets/css/styles.css

@@ -8,6 +8,7 @@
 @import "components/steps.css";
 @import "components/search.css";
 @import "components/sidebar.css";
+@import "components/navbar.css";
 
 html {
   @apply text-base antialiased;
@@ -22,6 +23,7 @@ body {
 :root {
   --primary-hue: 212deg;
   --navbar-height: 4rem;
+  --menu-height: 3.75rem;
 }
 
 .dark {