Add about pages

app/models/problem.rb

@@ -11,11 +11,14 @@ class Problem < ApplicationRecord
     !!self.translation
   end
 
-
   def original_url
     "https://projecteuler.net/problem=#{self.id}"
   end
 
+  def self.translated_count
+    Problem.count(:translation_id)
+  end
+
   def self.update_count(new_count)
     old_count = Problem.count
     raise ArgumentError, "new count has to be larger than old count" if new_count < old_count