Document MaskedTextField Component

[hyyan]

See #362

The MaskedTextField is a specialized text field that allows users to input text in a predefined format. The format is determined by a mask, which is a string specifying the characters the user can enter.

Features (The order is arbitrary):

• Supported Masks: Various mask patterns are supported, enabling flexible text formatting.
• Combining Masks with Patterns: Masks can be combined with custom patterns to meet specific formatting requirements.
• Restore Method: This feature allows users to reset the field's value either by pressing the restore key (typically ESC) or by invoking the restoreValue() method programmatically.