Update Kotlin documentation (1.6.20)

assets/javascripts/templates/pages/about_tmpl.coffee

@@ -479,7 +479,7 @@ credits = [
     'https://raw.githubusercontent.com/koajs/koa/master/LICENSE'
   ], [
     'Kotlin',
-    '2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors',
+    '2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors',
     'Apache',
     'https://raw.githubusercontent.com/JetBrains/kotlin/master/license/LICENSE.txt'
   ], [

lib/docs/scrapers/kotlin.rb

@@ -27,12 +27,12 @@ module Docs
     end
 
     options[:attribution] = <<-HTML
-      &copy; 2010&ndash;2021 JetBrains s.r.o. and Kotlin Programming Language contributors<br>
+      &copy; 2010&ndash;2022 JetBrains s.r.o. and Kotlin Programming Language contributors<br>
       Licensed under the Apache License, Version 2.0.
     HTML
 
     version '1.6' do
-      self.release = '1.6.0'
+      self.release = '1.6.20'
     end
 
     version '1.4' do