Update databricks_template_schema.json for scala-job examples (#90)

This PR addresses some feedback from the bug bash, makes the
instructions more clear and fix the issue by accepting trailing slashes.

---------

Co-authored-by: Pieter Noordhuis <pcnoordhuis@gmail.com>
Co-authored-by: Garland Zhang <garland.zhang@databricks.com>

Author: 3 people

contrib/templates/scala-job/databricks_template_schema.json

@@ -10,10 +10,10 @@
     },
     "artifacts_dest_path": {
       "type": "string",
-      "description": "\nPlease provide the Volumes destination path in Databricks where the directory will be created containing the JAR and other artifacts to store. [example: /Volumes/abcdef1234567890].\nNote: Only when using Standard clusters, your admin must allowlist the Volumes JAR path you specify for your workspace (see https://docs.databricks.com/en/data-governance/unity-catalog/manage-privileges/allowlist.html)",
+      "description": "\nPlease provide the Unity Catalog volume destination path in Databricks where the directory will be created containing the JAR and other artifacts to store. [example: /Volumes/abcdef1234567890].\nNote: Only when using Standard clusters, your admin must allowlist the volume JAR path you specify for your workspace (see https://docs.databricks.com/en/data-governance/unity-catalog/manage-privileges/allowlist.html)",
       "order": 2,
-      "pattern": "^/Volumes(?:/[a-z0-9_-]+)+$",
-      "pattern_match_failure_message": "Path must be of the form ^/Volumes(?:/[a-z0-9_-]+)+$"
+      "pattern": "^/Volumes(?:/[a-z0-9_-]+)+/?$",
+      "pattern_match_failure_message": "Please enter a valid path like /Volumes/my-folder/. Only lowercase letters, numbers, dashes, and underscores are allowed in folder names."
     }
   }
 }