Update title in custom_template notebook (TGSAI#735)

Author: tasansal

docs/tutorials/custom_template.ipynb

@@ -5,7 +5,7 @@
    "id": "85114119ae7a4db0",
    "metadata": {},
    "source": [
-    "# Create and Register a Custom Template\n",
+    "# MDIO Template Usage\n",
     "\n",
     "```{article-info}\n",
     ":author: Altay Sansal\n",