fix types.

src/learn/index.vue

@@ -1,5 +1,9 @@
-<script setup lang="ts"></script>
+<script setup lang="ts">
+import Md from "./step-1/index.md"
+</script>
 
-<template>learn</template>
+<template>
+  <Md />
+</template>
 
 <style scoped></style>