Issue with guide example

[jorgen-17]

Hey, loving ldapjs so far, its definately been making learning and setting up ldap a lot more clearer than using slapd directly. Anyways just noticed there is a mistake in the examples located at http://ldapjs.org/guide.html. The examples look for a cn property in rdns[0] i.e.

req.dn.rdns[0].cn

but they should be looking for it in rdns[0].attrs i.e.

req.dn.rdns[0].attrs.cn

Other than this the documentation is a huge improvement over the slapd docs I've seen out there. Thanks for putting this together!