Add a format option for converting posts to markdown via Python's html2text.

lib/jekyll/migrators/tumblr.rb

@@ -8,7 +8,7 @@ require 'date'
 
 module Jekyll
   module Tumblr
-    def self.process(url, grab_images = false)
+    def self.process(url, grab_images = false, format = "html")
       current_page = 0
 
       while true
@@ -75,6 +75,7 @@ module Jekyll
           name = "#{Date.parse(post['date']).to_s}-#{title.downcase.strip.gsub(' ', '-').gsub(/[^\w-]/, '')}.#{format}"
 
           if title != nil || content != nil && name != nil
+            content = %x[echo '#{content.gsub("'", "''")}' | html2text] if format == "md"
             File.open("_posts/tumblr/#{name}", "w") do |f|
 
               f.puts <<-HEADER