Update DOM documentation

Fixes deprecated/experimental/non-standard/obsolete icons.

Fixes #1529.

lib/docs/filters/mdn/clean_html.rb

@@ -49,7 +49,7 @@ module Docs
           node.name = 'strong'
         end
 
-        css('svg.deprecated').each do |node|
+        css('svg.icon.deprecated', 'svg.icon.experimental', 'svg.icon.non-standard', 'svg.icon.obsolete').each do |node|
           node.name = 'span'
           node.content = node.content
         end

lib/docs/scrapers/mdn/dom.rb

@@ -8,5 +8,7 @@ module Docs
 
     options[:root_title] = 'DOM'
 
+    # self.release = '2021-04-29'
+
   end
 end