Correct typo and improve formatting in is_leap

Fix typo in docstring and formatting in is_leap function.

Author: rajeshsola

myleap.py

@@ -2,5 +2,5 @@
 
 
 def is_leap(yy):
-    """Functin to check given year is leap or not."""
-    return yy % 400 == 0  or (yy % 4 == 0 and yy % 100 != 0)
+  """Functin to check given year is leap or not."""
+  return yy % 400 == 0  or (yy % 4==0 and yy % 100 != 0)