docs: improve forms usage with examples

docs/content/3.forms/1.input.md

@@ -5,11 +5,22 @@ description: Display an input field.
 
 ## Usage
 
-::component-card
----
-baseProps:
-  name: 'input'
----
+Use a `v-model` to make the Input reactive.
+
+::component-example
+#default
+:input-example
+
+#code
+```vue
+<script setup>
+const value = ref('')
+</script>
+
+<template>
+  <UInput v-model="value" />
+</template>
+```
 ::
 
 ### Style