route breadcrumbs, improve sidebar, basic folder layout

components/ui/collapsible/CollapsibleContent.vue

@@ -0,0 +1,14 @@
+<script setup lang="ts">
+import { CollapsibleContent, type CollapsibleContentProps } from 'reka-ui'
+
+const props = defineProps<CollapsibleContentProps>()
+</script>
+
+<template>
+  <CollapsibleContent
+    data-slot="collapsible-content"
+    v-bind="props"
+  >
+    <slot />
+  </CollapsibleContent>
+</template>