Update input examples for change in axe-core rule

Placeholders now count as labels for inputs. See
- dequelabs/axe-core#2448
- dequelabs/axe-core#2413
- https://www.w3.org/TR/html-aam-1.0/#input-type-text-input-type-password-input-type-search-input-type-tel-input-type-email-input-type-url-and-textarea-element-accessible-name-computation

demo/src/stories/input.stories.jsx

@@ -17,21 +17,21 @@ export const Input1 = () => (
 );
 Input1.storyName = 'Input with label (should pass)';
 
-export const Input2 = () => <Input placeholder="Favorite coffee" />;
+export const Input2 = () => <Input />;
 Input2.storyName = 'Input without label (should fail)';
 
-export const Input3 = () => <Input placeholder="Favorite coffee" />;
+export const Input3 = () => <Input />;
 Input3.storyName = 'Input without label but skipped (should pass)';
 Input3.parameters = {
   axe: {
     disabled: true,
   },
 };
 
-export const Input4 = () => <Input placeholder="Favorite coffee" role="wut-the-wut" />;
+export const Input4 = () => <Input role="wut-the-wut" />;
 Input4.storyName = 'Input without label and invalid role (should fail)';
 
-export const Input5 = () => <Input placeholder="Favorite coffee" />;
+export const Input5 = () => <Input />;
 Input5.storyName = 'Input without label but "label" rule is disabled (should pass)';
 Input5.parameters = {
   axe: {