Update pkpy.pyi

include/typings/pkpy.pyi

@@ -18,6 +18,9 @@ def memory_usage() -> str:
 def is_user_defined_type(t: type) -> bool:
     """Check if a type is user-defined. This means the type was created by executing python `class` statement."""
 
+def enable_full_buffering_mode() -> None:
+    """Enable full buffering mode for ASCII drawings."""
+
 def currentvm() -> int:
     """Return the current VM index."""