Make CardList Title customizable.

[angelinazhang9999990]

Prerequisites

• I have read the Contributing Guidelines.
• I have not leaked any internal/restricted information like screenshots, videos, code snippets, links etc.

Suggestion / feature request

This is regrading CardList component.

Current behavior

Currently CardList component allows pass a string as a title of card list.

Expect

It would be nice if I can just customize the content of card list title block instead of simply passing a string property.

Use case

The use case is that I have a card list which includes different type of cards. It would be nice if I can have pills within title block as an overview of how many cards for each type. I can even filter cards when click the pill.