Update state names in json-doc lexer (#1364)

The json-doc lexer inherits from the JSON lexet. As a consequence, an
earlier refactoring of the JSON lexer that, among other things,
introduced two new states broke the json-doc lexer. This commit corrects
the references to these states.

lib/rouge/lexers/json_doc.rb

@@ -6,16 +6,17 @@ module Lexers
     load_lexer 'json.rb'
 
     class JSONDOC < JSON
-      desc "JavaScript Object Notation with extenstions for documentation"
+      desc "JavaScript Object Notation with extensions for documentation"
       tag 'json-doc'
 
-      prepend :root do
+      prepend :name do
         rule %r/([$\w]+)(\s*)(:)/ do
           groups Name::Attribute, Text, Punctuation
         end
+      end
 
+      prepend :value do
         rule %r(/[*].*?[*]/), Comment
-
         rule %r(//.*?$), Comment::Single
         rule %r/(\.\.\.)/, Comment::Single
       end