Ruff fixes

Author: ikostan

cater-waiter/sets.py

@@ -129,6 +129,8 @@ def separate_appetizers(dishes: list, appetizers: list) -> list:
 
 def singleton_ingredients(dishes: list[set[str]], intersection) -> set:
     """
+    Determine singleton ingredient.
+
     Determine which `dishes` have a singleton ingredient (an ingredient that
     only appears once across dishes).
 

triangle/triangle.py

@@ -14,6 +14,8 @@ def equilateral(sides: list) -> bool:
 
 def isosceles(sides: list) -> bool:
     """
+    Verify isosceles triangle.
+
     An isosceles triangle has at least two sides the same length.
 
     (It is sometimes specified as having exactly two sides the same length,