Add messageUseStyler builder

This allows the user to pass a function which automatically converts
the message's String to the AttributedString displayed in each message
bubble.

Author: matthewrfennell

README.md

@@ -48,7 +48,7 @@
 - Can display a fullscreen menu on long press a message cell (automatically shows scroll for big messages)
 - Supports "reply to message" via message menu or through a closure. Remove and edit are **coming soon**
 - This library allows to send the following content in messages in any combination:
-    - Text with/without markdown
+    - Arbitrarily styled text with `AttributedString` or markdown
     - Photo/video
     - Audio recording
     **Coming soon:**
@@ -277,6 +277,7 @@ Please use `mediaPickerTheme` in a similar fashion to customize the built-in pho
 `avatarSize` - the default avatar is a circle, you can specify its diameter here 
 `tapAvatarClosure` - closure to call on avatar tap   
 `messageUseMarkdown` - use markdown (e.g. ** to make something bold) or not
+`messageUseStyler` - pass a function that converts the message's `String` to the styled `AttributedString`
 `showMessageTimeView` - show timestamp in a corner of the message   
 `setMessageFont` - pass custom font to use for messages   
 

Sources/ExyteChat/ChatView/ChatView.swift

@@ -600,8 +600,12 @@ public extension ChatView {
     }
 
     func messageUseMarkdown(_ messageUseMarkdown: Bool) -> ChatView {
+        return messageUseStyler(String.markdownStyler)
+    }
+
+    func messageUseStyler(_ styler: @escaping (String) -> AttributedString) -> ChatView {
         var view = self
-        view.messageStyler = String.markdownStyler
+        view.messageStyler = styler
         return view
     }