Add yard, yardstick and yard-junk to document the gem

Rakefile

@@ -4,13 +4,27 @@ require 'bundler/audit/task'
 require 'bundler/gem_tasks'
 require 'rspec/core/rake_task'
 require 'rubocop/rake_task'
+require 'yaml'
+require 'yard/rake/yardoc_task'
+require 'yard-junk/rake'
+require 'yardstick/rake/measurement'
+require 'yardstick/rake/verify'
+
+yardstick_options = YAML.load_file('.yardstick.yml')
 
 Bundler::Audit::Task.new
 RSpec::Core::RakeTask.new(:spec)
 RuboCop::RakeTask.new
+YARD::Rake::YardocTask.new
+YardJunk::Rake.define_task
+Yardstick::Rake::Measurement.new(:yardstick_measure, yardstick_options)
+Yardstick::Rake::Verify.new
 
 task default: %i[spec rubocop]
 
+# Remove the report on rake clobber
+CLEAN.include('measurements', 'doc', '.yardoc', 'tmp')
+
 # Delete these files and folders when running rake clobber.
 CLOBBER.include('coverage', '.rspec_status')