Merge pull request #445 from jjyyxx/patch-1

fix typo

lib/ruler.js

@@ -104,7 +104,7 @@ Ruler.prototype.__compile__ = function () {
  *
  * ##### Example
  *
- * Replace existing typorgapher replacement rule with new one:
+ * Replace existing typographer replacement rule with new one:
  *
  * ```javascript
  * var md = require('markdown-it')();