Fix example url

[dhruvdutt]

The URL mentioned in the sample example is invalid / 404.

http://isaacs.couchone.com/registry/_all_docs

var request = require('request')
  , JSONStream = require('JSONStream')
  , es = require('event-stream')

request({url: 'http://isaacs.couchone.com/registry/_all_docs'})
  .pipe(JSONStream.parse('rows.*'))
  .pipe(es.mapSync(function (data) {
    console.error(data)
    return data
  }))