Add Kotlin documentation

Added documentation for the Kotlin programming language.

The documentation comes from the [Kotlin Standard Library
documentation](https://kotlinlang.org/api/latest/jvm/stdlib/index.html)
at the [official Kotlin website](https://kotlinlang.org). It is all
licensed under the [Apache License, Version
2.0](https://github.com/JetBrains/kotlin-web-site/blob/master/LICENSE).

lib/docs/filters/kotlin/clean_html.rb

@@ -0,0 +1,9 @@
+module Docs
+  class Kotlin
+    class CleanHtmlFilter < Filter
+      def call
+        doc
+      end
+    end
+  end
+end

lib/docs/filters/kotlin/entries.rb

@@ -0,0 +1,51 @@
+module Docs
+  class Kotlin
+    class EntriesFilter < Docs::EntriesFilter
+      def get_name
+        if at_css('h1')
+          name = at_css('h1').text
+          module_name = breadcrumbs[1]
+
+          "#{module_name}.#{name}"
+        elsif at_css('h2')
+          at_css('h2').text.gsub 'Package ', ''
+        elsif at_css('h3')
+          at_css('h3').text
+        end
+      end
+
+      def get_type
+        if package? || top_level? && !extensions?
+          breadcrumbs[1]
+        else
+          "miscellaneous"
+        end
+      end
+
+      private
+
+      def breadcrumbs
+        container = at_css('.api-docs-breadcrumbs')
+
+        if container
+          links = container.children.select.with_index { |_, i| i.even? }
+          links.map &:text
+        else
+          []
+        end
+      end
+
+      def top_level?
+        breadcrumbs.size == 3
+      end
+
+      def extensions?
+        get_name.start_with? 'Extensions'
+      end
+
+      def package?
+        breadcrumbs.size == 2
+      end
+    end
+  end
+end

lib/docs/scrapers/kotlin.rb

@@ -0,0 +1,21 @@
+module Docs
+  class Kotlin < UrlScraper
+    self.type = 'kotlin'
+    self.release = '1.0.2'
+    self.base_url = 'https://kotlinlang.org/api/latest/jvm/stdlib/'
+    self.root_path = 'index.html'
+    self.links = {
+      home: 'https://kotlinlang.org/',
+      code: 'https://github.com/JetBrains/kotlin'
+    }
+
+    html_filters.push 'kotlin/entries', 'kotlin/clean_html'
+
+    options[:container] = '.page-content'
+
+    options[:attribution] = <<-HTML
+      &copy; 2016 JetBrains<br>
+      Licensed under the Apache License, Version 2.0.
+    HTML
+  end
+end

public/icons/docs/kotlin/SOURCE

@@ -0,0 +1 @@
+https://upload.wikimedia.org/wikipedia/commons/b/b5/Kotlin-logo.png