Make Literal::Number base09 per spec

Previously
- base0B: Strings, Inherited Class, Markup Code, Diff Inserted

Now:
- base09 - Integers, Boolean, Constants, XML Attributes, Markup Link Url
           ^^^^^^^^

lib/rouge/themes/base16.rb

@@ -63,7 +63,8 @@ def self.make_light!
 
       style Keyword::Constant,
             Keyword::Declaration,
-            Keyword::Type, :fg => :base09
+            Keyword::Type,
+            Literal::Number, :fg => :base09
 
       style Comment::Preproc,
             Name::Class,
@@ -72,7 +73,6 @@ def self.make_light!
             Name::Tag, :fg => :base0A
 
       style Generic::Inserted,
-            Literal::Number,
             Literal::String,
             Literal::String::Symbol, :fg => :base0B