update chapter23 method 1
Merge pull request #138 from liuyang1/master

update chapter23 method 1
write Makefile based on https://github.com/evangoer/pandoc-ebook-template
Tested: epub & html.
Not Tested: pdf
      I haven’t install latex in my mac. I will try this later.
BTW: generated html is not elegant, I will write a tool to generate html exactly like github.
Merge remote-tracking branch 'upstream/master'
Merge branch 'try_makefile'