Example in READEME for how to use markdown.js in browser is wrong

[xlwang-bupt]

• If we follow the readme to use this markdown.js in browser, It will
  not be useful, return 'expose is undefined' and 'markdown is
  undefined',so i change some code in this html in READEME and
  lib/markdown.js.
• It maybe not be wrong in old way which READEME described, it may be
  used in node environment,not run in just simply browser + html + js
• I change some code ,so i could use it

[ashb]

The problem with the example is referring to an old way - but we now don't store a compiled version in the repo. You can get the a 'compiled' version of the source from the https://github.com/evilstreak/markdown-js/releases page.

The change as you have it would break non-browser use so can't be accepted, but an improvement to the docs to point at that and update the path in the example would be handy. Thanks!