adding unread message in get recent conversation

[gaelsapori]

Resolves #5 I have added unread messages count on getRecentConversation ChatMessage model

[adeelibr]

Thank you for making this PR, I'll keep this open. If other people want to access this information, only reason I am not adding this to the codebase is because then i'll have to update the entire tutorial and add more context to the docs/guide.

I really appreciate you taking the timeout to add more information. 👍