Add more examples

[My-]

Currently, there are only two examples. It would be nice to have more.
Possible examples:

• Adaptive Card

[My-]

Please suggest more examples.

[aknarts]

Adaptive cards are a very complicated matter... Every Webex Teams client supports different sets of card features, so the official support for 1.2 is difficult. AFAIK the best support is on the Web client, the worst on the desktop side of things. So if you use them make sure it renders on all clients and/or provide reasonable fallback in terms of markdown/text

[Nabushika]

Added a small adaptive card example :)