added yml alias for yaml code highlighting

plugins/code_block.rb

@@ -79,6 +79,7 @@ module Jekyll
       if @filetype
         @filetype = 'objc' if @filetype == 'm'
         @filetype = 'perl' if @filetype == 'pl'
+        @filetype = 'yaml' if @filetype == 'yml'
         source += " #{highlight(code, @filetype)}</figure></div>"
       else
         source += "<pre><code>" + code.lstrip.rstrip.gsub(/</,'&lt;') + "</code></pre></figure></div>"

plugins/include_code.rb

@@ -55,6 +55,7 @@ module Jekyll
         @filetype = file.extname.sub('.','')
         @filetype = 'objc' if @filetype == 'm'
         @filetype = 'perl' if @filetype == 'pl'
+        @filetype = 'yaml' if @filetype == 'yml'
         title = @title ? "#{@title} (#{file.basename})" : file.basename
         url = "#{context.registers[:site].config['url']}/#{code_dir}/#{@file}"
         source = "<div><figure role=code><figcaption><span>#{title}</span> <a href='#{url}'>download</a></figcaption>\n"