Create a design document for support for multimodal natural expressions

[SasinduDilshara]

Current Limitation

Sub issue of #8016

Suggested Improvement

Creating a design document for

• Input natural expressions with multi modals data
• Output multi modals data

Version

No response

[SasinduDilshara]

The design document can be found in https://docs.google.com/document/d/1nDdxIMiPbc0n5zkdKM4xrDnFGnd3aIoOEKNl8nwNi7U/edit?usp=sharing