Add example implementation of DndCharacter class

Co-authored-by: KOTP <[email protected]>

exercises/practice/dnd-character/.meta/example.rb

@@ -0,0 +1,43 @@
+module Die
+  module_function
+
+  def roll(roll: 4, die: 6, remove_lowest: 1)
+    roll.times.map { rand(1..die) }.sort.pop(roll - remove_lowest).sum
+  end
+end
+
+module Modifiable
+  def modifier(ability_score)
+    ability_score / 2 - 5
+  end
+end
+
+class DndCharacter
+  extend Modifiable
+
+  BASE_HITPOINTS = 10
+
+  private_constant :BASE_HITPOINTS
+
+  private
+  def initialize
+    @strength     = Die.roll
+    @dexterity    = Die.roll
+    @constitution = Die.roll
+    @intelligence = Die.roll
+    @wisdom       = Die.roll
+    @charisma     = Die.roll
+
+    @hitpoints    = BASE_HITPOINTS + self.class.modifier(constitution)
+  end
+
+  public
+
+  attr_reader :strength,
+    :dexterity,
+    :constitution,
+    :intelligence,
+    :wisdom,
+    :charisma,
+    :hitpoints
+end