Add title to subnetworks graph

Author: liamjberrisford

programme_information/intro_to_version_control.ipynb

@@ -87,7 +87,7 @@
     "\n",
     "# Create a display HTML block with a title\n",
     "html_str = f\"<div style='text-align: center;'><h3>Pre-Reqs Subnetwork</h3></div>\"\n",
-    "html_str += f\"<iframe id='{iframe_id}' src='{file_name}' width='100%' height='750px' style='border:none;'></iframe>\"\n",
+    "html_str += f\"<iframe id='{iframe_id}' src='{file_name}' title='Workshop Prerequisites Graph Subnetwork' width='100%' height='750px' style='border:none;'></iframe>\"\n",
     "\n",
     "# Include JavaScript to adjust the iframe height\n",
     "js_code = f\"\"\"\n",