try make note box prettier

examples/notebooks/ex04_parallel_processing.ipynb

@@ -11,22 +11,24 @@
     "\n",
     "<div class=\"alert alert-warning\">\n",
     "\n",
-    "<strong>Note:</strong> Parallel processing is platform dependent and may not\n",
+    "<strong>Note</strong> \n",
+    "\n",
+    "Parallel processing is platform dependent and may not\n",
     "always work. The current implementation works well for Linux users, though this\n",
     "will likely change with Python 3.13 and higher. For Windows users, parallel\n",
     "solving does not work when called directly from Jupyter Notebooks or IPython.\n",
     "To use parallel solving on Windows, the following code should be used in a\n",
-    "Python file:\n",
+    "Python file. \n",
+    "\n",
+    "</div>\n",
     "\n",
-    "<pre><code class=\"python\">\n",
+    "```python\n",
     "from multiprocessing import freeze_support\n",
     "\n",
     "if __name__ == \"__main__\":\n",
     "    freeze_support()\n",
     "    pstore.apply(\"models\", some_func, parallel=True)\n",
-    "</code></pre>\n",
-    "\n",
-    "</div>"
+    "```"
    ]
   },
   {