Implement Public API's from ChatCore and ChatUI #68
Description
As a user I want the chat API's to be simple to discover and use.
AC:
- Primary entry points are
- http://github.com/getditto/DittoChat/blob/main/sdks/swift/Sources/DittoChatUI/DittoChatUI.swift
- https://github.com/getditto/DittoChat/blob/main/sdks/swift/Sources/DittoChatCore/DittoChat.swift
- Implement public API's with a strong focus on replicating the ones in the two files above with others that make sense and exist