feat: rewrite to use app config and rework docs (#143)

Co-authored-by: Daniel Roe <daniel@roe.dev>
Co-authored-by: Sébastien Chopin <seb@nuxt.com>

docs/components/content/examples/ModalExampleBasic.vue

@@ -0,0 +1,15 @@
+<script setup>
+const open = ref(false)
+</script>
+
+<template>
+  <div>
+    <UButton label="Open" @click="open = true" />
+
+    <UModal v-model="open">
+      <div class="p-4">
+        <Placeholder class="h-48" />
+      </div>
+    </UModal>
+  </div>
+</template>