added custom button widget in toolbar

lib/src/models/themes/quill_custom_button.dart

@@ -1,11 +1,14 @@
 import 'package:flutter/material.dart';
 
 class QuillCustomButton {
-  const QuillCustomButton({this.icon, this.onTap});
+  const QuillCustomButton({this.icon, this.onTap, this.child});
 
   ///The icon widget
   final IconData? icon;
 
   ///The function when the icon is tapped
   final VoidCallback? onTap;
+
+  ///The customButton placeholder
+  final Widget? child;
 }

lib/src/widgets/toolbar.dart

@@ -485,7 +485,13 @@ class QuillToolbar extends StatelessWidget implements PreferredSizeWidget {
               endIndent: 12,
               color: Colors.grey.shade400,
             ),
-        for (var customButton in customButtons)
+        for (var customButton in customButtons) ...[
+          if (customButton.child != null) ...[
+            InkWell(
+              onTap: customButton.onTap,
+              child: customButton.child,
+            ),
+          ] else ...[
             QuillIconButton(
               highlightElevation: 0,
               hoverElevation: 0,
@@ -496,6 +502,8 @@ class QuillToolbar extends StatelessWidget implements PreferredSizeWidget {
               afterPressed: afterButtonPressed,
             ),
           ],
+        ],
+      ],
     );
   }