doc: update docstring for _validate_instance_deprecation

Author: Shibo Xing

src/sagemaker/image_uris.py

@@ -367,7 +367,7 @@ def _config_for_framework_and_scope(framework, image_scope, accelerator_type=Non
 
 
 def _validate_instance_deprecation(framework, instance_type, version):
-    """check if instance type is deprecated for a certain framework with a certain version"""
+    """Check if instance type is deprecated for a certain framework with a certain version"""
     if (
         framework == "pytorch"
         and _get_instance_type_family(instance_type) == "p2"