Add date-time to documented default formats

Author: sirosen

src/check_jsonschema/cli/main_command.py

@@ -71,7 +71,7 @@ def pretty_helptext_list(values: list[str] | tuple[str, ...]) -> str:
 
 'check-jsonschema' supports format checks with appropriate libraries installed,
 including the following formats by default:
-    date, email, ipv4, ipv6, regex, uuid
+    date, date-time, email, ipv4, ipv6, regex, uuid
 
 \b
 For the "regex" format, there are multiple modes which can be specified with