refactor: redesign module system

src/shims-vue.d.ts

@@ -0,0 +1,11 @@
+import { defineComponent } from 'vue'
+
+declare module '*.vue' {
+  const Component: ReturnType<typeof defineComponent>
+  export default Component
+}
+
+declare module '*.md' {
+  const Component: ReturnType<typeof defineComponent>
+  export default Component
+}