add error formatting recipe

recipes/error-formatting.md

@@ -15,7 +15,7 @@ export const router = trpc.router<Context>()
       data: {
         ...shape.data,
         zodError:
-          error.code === 'BAD_USER_INPUT'
+          error.code === 'BAD_REQUEST'
           && error.cause instanceof ZodError
             ? error.cause.flatten()
             : null,
@@ -27,5 +27,15 @@ export const router = trpc.router<Context>()
 ### Usage in Vue
 
 ```html
+<script setup lang="ts">
+const { error } = await useAsyncQuery(['getUser', { id: 69 }])
+</script>
 
+<template>
+  <pre v-if="error?.data?.zodError">
+    {{ JSON.stringify(error.data.zodError, null, 2) }}
+  </pre>
+</template>
 ```
+
+Learn more about error formatting [here](https://trpc.io/docs/error-formatting).