add missing RAC Checkbox/CheckboxGroup story files (#6420)

Co-authored-by: Robert Snow <rsnow@adobe.com>
Co-authored-by: Yihui Liao <44729383+yihuiliao@users.noreply.github.com>

Author: 3 people

packages/react-aria-components/stories/Checkbox.stories.tsx

@@ -0,0 +1,21 @@
+import {Checkbox} from 'react-aria-components';
+import React from 'react';
+import './styles.css';
+
+
+export default {
+  title: 'React Aria Components'
+};
+
+export const CheckboxExample = () => {
+  return (
+    <Checkbox>
+      <div className="checkbox">
+        <svg viewBox="0 0 18 18" aria-hidden="true">
+          <polyline points="1 9 7 14 15 4" />
+        </svg>
+      </div>
+      Unsubscribe
+    </Checkbox>
+  );
+};

packages/react-aria-components/stories/CheckboxGroup.stories.tsx

@@ -0,0 +1,34 @@
+import {Checkbox, CheckboxGroup, Label} from 'react-aria-components';
+import React from 'react';
+import './styles.css';
+
+
+export default {
+  title: 'React Aria Components'
+};
+
+export const CheckboxGroupExample = () => {
+  return (
+    <CheckboxGroup>
+      <Label>Favorite sports</Label>
+      <Checkbox value="soccer">
+        <div className="checkbox" aria-hidden="true">
+          <svg viewBox="0 0 18 18"><polyline points="1 9 7 14 15 4" /></svg>
+        </div>
+        Soccer
+      </Checkbox>
+      <Checkbox value="baseball">
+        <div className="checkbox" aria-hidden="true">
+          <svg viewBox="0 0 18 18"><polyline points="1 9 7 14 15 4" /></svg>
+        </div>
+        Baseball
+      </Checkbox>
+      <Checkbox value="basketball">
+        <div className="checkbox" aria-hidden="true">
+          <svg viewBox="0 0 18 18"><polyline points="1 9 7 14 15 4" /></svg>
+        </div>
+        Basketball
+      </Checkbox>
+    </CheckboxGroup>
+  );
+};