docs: update @input other inputs example with $event.target.value

Author: sadeghbarati

apps/v4/content/docs/forms/02.tanstack-form.md

@@ -57,7 +57,7 @@ Here's a basic example of a form using TanStack Form with the `<Field />` compon
             :name="field.name"
             :model-value="field.state.value"
             @blur="field.handleBlur"
-            @input="field.handleChange"
+            @input="field.handleChange($event.target.value)"
             :aria-invalid="isInvalid(field)"
             placeholder="Login button not working on mobile"
             autocomplete="off"
@@ -237,7 +237,7 @@ function isInvalid(field) {
         :name="field.name"
         :model-value="field.state.value"
         @blur="field.handleBlur"
-        @input="field.handleChange"
+        @input="field.handleChange($event.target.value)"
         type="email"
         :aria-invalid="isInvalid(field)"
       />
@@ -634,7 +634,7 @@ Access individual array items using bracket notation: `fieldName[index].property
             :name="subField.name"
             :model-value="subField.state.value"
             @blur="subField.handleBlur"
-            @input="subField.handleChange"
+            @input="field.handleChange($event.target.value)"
             :aria-invalid="isSubFieldInvalid(subField)"
             placeholder="[email protected]"
             type="email"