feat: POST /api/v3/chats, chat room creation, plus openAPI docs update

src/api/index.js

@@ -5,6 +5,7 @@ module.exports = {
 	groups: require('./groups'),
 	topics: require('./topics'),
 	posts: require('./posts'),
+	chats: require('./chats'),
 	categories: require('./categories'),
 	flags: require('./flags'),
 };