bring back bread crumbs

libs/template/templates/default-python/template/{{.project_name}}/tests/main_test.py.tmpl

@@ -1,3 +1,10 @@
+{{/*
+  The below works around a problematic error message from Databricks Connect.
+  The standard SparkSession is supported in all configurations (workspace, IDE,
+  all runtime versions, CLI). But on the CLI it currently gives a confusing
+  error message if SPARK_REMOTE is not set. Here we import the DatabricksSession
+  as SparkSession so the rest of the code looks as expected.
+*/}}
 from databricks.connect import DatabricksSession as SparkSession
 from pytest import fixture
 from {{.project_name}} import main
@@ -5,6 +12,9 @@ from {{.project_name}} import main
 
 @fixture(scope="session")
 def spark():
+    # Create a new Databricks Connect session. If this fails, you should
+    # check that you have configured Databricks Connect correctly.
+    # See https://docs.databricks.com/dev-tools/databricks-connect.html.
     spark = SparkSession.builder.getOrCreate()
     yield spark
     spark.stop()