Add YARD docs for Faker::Kpop. (faker-ruby#1850)

lib/faker/default/kpop.rb

@@ -3,26 +3,80 @@
 module Faker
   class Kpop < Base
     class << self
+      ##
+      # Produces the name of a 1990's 'OG' K-Pop group.
+      #
+      # @return [String]
+      #
+      # @example
+      #   Faker::Kpop.i_groups #=> "Seo Taiji and Boys"
+      #
+      # @faker.version 1.8.5
       def i_groups
         fetch('kpop.i_groups')
       end
 
+      ##
+      # Produces the name of a 2000's K-Pop group.
+      #
+      # @return [String]
+      #
+      # @example
+      #   Faker::Kpop.ii_groups #=> "Girls' Generation"
+      #
+      # @faker.version 1.8.5
       def ii_groups
         fetch('kpop.ii_groups')
       end
 
+      ##
+      # Produces the name of a 2010's K-Pop group.
+      #
+      # @return [String]
+      #
+      # @example
+      #   Faker::Kpop.iii_groups #=> "Trouble Maker"
+      #
+      # @faker.version 1.8.5
       def iii_groups
         fetch('kpop.iii_groups')
       end
 
+      ##
+      # Produces the name of a K-Pop girl group.
+      #
+      # @return [String]
+      #
+      # @example
+      #   Faker::Kpop.girl_groups #=> "2NE1"
+      #
+      # @faker.version 1.8.5
       def girl_groups
         fetch('kpop.girl_groups')
       end
 
+      ##
+      # Produces the name of a K-Pop boy band.
+      #
+      # @return [String]
+      #
+      # @example
+      #   Faker::Kpop.boy_bands #=> "Exo"
+      #
+      # @faker.version 1.8.5
       def boy_bands
         fetch('kpop.boy_bands')
       end
 
+      ##
+      # Produces the name of a solo K-Pop artist.
+      #
+      # @return [String]
+      #
+      # @example
+      #   Faker::Kpop.solo #=> "T.O.P"
+      #
+      # @faker.version 1.8.5
       def solo
         fetch('kpop.solo')
       end