docs: fix typo in docs (#313)

Changes:
- flat should be flag

UnleashClient/__init__.py

@@ -347,7 +347,7 @@ def is_enabled(
 
         Notes:
 
-        * If client hasn't been initialized yet or an error occurs, flat will default to false.
+        * If client hasn't been initialized yet or an error occurs, flag will default to false.
 
         :param feature_name: Name of the feature
         :param context: Dictionary with context (e.g. IPs, email) for feature toggle.
@@ -441,7 +441,7 @@ def get_variant(self, feature_name: str, context: Optional[dict] = None) -> dict
 
         Notes:
 
-        * If client hasn't been initialized yet or an error occurs, flat will default to false.
+        * If client hasn't been initialized yet or an error occurs, flag will default to false.
 
         :param feature_name: Name of the feature
         :param context: Dictionary with context (e.g. IPs, email) for feature toggle.