add Markdown detection and rendering

- Implement `containsMarkdown` function to identify messages with Markdown
- Utilize `flutter_markdown` package to render detected Markdown content
- Enhance chat UI to conditionally display plain text or formatted Markdown

frontend/lib/views/chat/agent_message_tile.dart

@@ -3,6 +3,7 @@ import 'dart:convert';
 import 'package:auto_gpt_flutter_client/models/chat.dart';
 import 'package:auto_gpt_flutter_client/views/chat/json_code_snippet_view.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter_markdown/flutter_markdown.dart';
 
 class AgentMessageTile extends StatefulWidget {
   final Chat chat;
@@ -26,6 +27,23 @@ class _AgentMessageTileState extends State<AgentMessageTile> {
     String jsonString = jsonEncode(widget.chat.jsonResponse);
     int artifactsCount = widget.chat.artifacts.length;
 
+    bool containsMarkdown(String text) {
+      // Regular expression to detect Markdown patterns like headers, bold, links, etc.
+      final RegExp markdownPattern = RegExp(
+        r'(?:\*\*|__).*?(?:\*\*|__)|' + // Bold
+            r'(?:\*|_).*?(?:\*|_)|' + // Italic
+            r'\[.*?\]\(.*?\)|' + // Links
+            r'!\[.*?\]\(.*?\)|' + // Images
+            r'#{1,6}.*', // Headers
+        multiLine: true,
+        caseSensitive: false,
+      );
+
+      return markdownPattern.hasMatch(text);
+    }
+
+    bool hasMarkdown = containsMarkdown(widget.chat.message);
+
     return LayoutBuilder(
       builder: (context, constraints) {
         double chatViewWidth = constraints.maxWidth;
@@ -62,10 +80,9 @@ class _AgentMessageTileState extends State<AgentMessageTile> {
                       Expanded(
                         child: Container(
                           padding: const EdgeInsets.fromLTRB(0, 10, 20, 10),
-                          child: Text(
-                            widget.chat.message,
-                            maxLines: null,
-                          ),
+                          child: hasMarkdown
+                              ? Markdown(data: widget.chat.message)
+                              : Text(widget.chat.message, maxLines: null),
                         ),
                       ),
                       ElevatedButton(