Add Angular Input Group Sample With Correct `id` and `for` Attributes

[georgianastasov]

Description

Add a new sample demonstrating the correct use of id on <input> matching the for attribute in <label>.

Current Input Group samples use a <label for="..."> but the corresponding <input> does not have an id, only a name. This breaks screen reader behavior, since for must point to a matching id, not name.

This causes labels to go unannounced in screen readers like JAWS and NVDA, and fails HTML validation checks.

Why Needed

• Proper for and id pairing is required for screen readers to associate labels with inputs.
• Missing id causes major accessibility issues and leads to confusion for users with assistive tech.
• HTML validators will raise warnings or errors.

Recommendations

• Include documentation explaining.