Fix env var name in conversion tutorial

notebooks/introductory/migration/1._Migrate_v1_model_to_v2.ipynb

@@ -10,9 +10,10 @@
     "If you've got an existing model built and saved with MedCAT v1, it will need to be converted into MedCAT v2's new format before it can be used.\n",
     "\n",
     "PS:\n",
-    "Technically, one can also convert a v1 model on the fly, automatically.\n",
-    "Though this can be disabled by setting the enviornmental variable `MEDCAT_AUTO_CONVERT_V1_TO_V2=false`.\n",
-    "However, this is not always adivisible since it results in much longer load times unless the model is later saved in the new format."
+    "MedCAT will automatically convert a v1 model to the correct v2 format upon loading.\n",
+    "Though this behaviour can be disabled by setting the enviornmental variable `MEDCAT_AVOID_LECACY_CONVERSION=true`.\n",
+    "When automatic conversion is enabled loading v1 models directly results in much longer load times.\n",
+    "It is generally recommended to instead convert the v1 model manually (saving it on disk) and subsequently loading it normally."
    ]
   },
   {