Technique ARIA21: Using aria-invalid to Indicate An Error Field 

In the example:

```
<div>
    <label for="email">Email (required)</label>
    <input type="text" name="email" id="email">
  </div>
```

Type should be email
See correct version:
```
<div>
    <label for="email">Email (required)</label>
    <input type="email" name="email" id="email">
  </div>
```

There's 3 markup examples all of them have the same mistake.