Add documentation examples for too-many-ancestors (#7067)

Co-authored-by: Vladyslav Krylasov <vladyslav.krylasov@gmail.com>
Co-authored-by: Pierre Sassoulas <pierre.sassoulas@gmail.com>

Author: 3 people

doc/data/messages/t/too-many-ancestors/bad.py

@@ -0,0 +1,24 @@
+class Animal: ...
+class BeakyAnimal(Animal): ...
+class FurryAnimal(Animal): ...
+class Swimmer(Animal): ...
+class EggLayer(Animal): ...
+class VenomousAnimal(Animal): ...
+class ProtectedSpecie(Animal): ...
+class BeaverTailedAnimal(Animal): ...
+class Vertebrate(Animal): ...
+
+
+# max of 7 by default, can be configured
+# each edge of a diamond inheritance counts
+class Playtypus(  # [too-many-ancestors]
+    BeakyAnimal,
+    FurryAnimal,
+    Swimmer,
+    EggLayer,
+    VenomousAnimal,
+    ProtectedSpecie,
+    BeaverTailedAnimal,
+    Vertebrate,
+):
+    pass

doc/data/messages/t/too-many-ancestors/details.rst

@@ -1 +1,33 @@
-# This is a placeholder for correct code for this message.
+class Animal:
+    beaver_tailed: bool
+    can_swim: bool
+    has_beak: bool
+    has_fur: bool
+    has_vertebrae: bool
+    lays_egg: bool
+    protected_specie: bool
+    venomous: bool
+
+
+class Invertebrate(Animal):
+    has_vertebrae = False
+
+
+class Vertebrate(Animal):
+    has_vertebrae = True
+
+
+class Mammal(Vertebrate):
+    has_beak = False
+    has_fur = True
+    lays_egg = False
+    venomous = False
+
+
+class Playtypus(Mammal):
+    beaver_tailed = True
+    can_swim = True
+    has_beak = True
+    lays_egg = False
+    protected_specie = True
+    venomous = True