Update Group chat feature (design draft)

Group-chat-feature-(design-draft).md

@@ -175,6 +175,16 @@ The commit message will be the following:
 
 For now, "mode" accepts values 0 (ONE_TO_ONE), 1 (ADMIN_INVITES_ONLY), 2 (INVITES_ONLY), 3 (PUBLIC)
 
+## Conversations requests specification
+
+Conversations requests are represented by a **Map<String, String>** with the following keys:
+
++ id: the conversation id
++ from: uri of the sender
++ received: timestamp
+
+TODO: title? avatar?
+
 # Used protocols
 
 ## Git