Add '×' conversion to 'x'

[atduarte]

No description provided.

[lillem4n]

Since this repo does not seem to be accepting pull requests, I've forked it, added this and some other pull requests and published another node module with the updates; https://github.com/larvit/larvitslugify
I've added you to contributors because you contributed. :)

[vfonic]

@lillem4n great approach! Thanks!

[Trott]

The correct repo for the slug module is now https://github.com/Trott/slug. This repo has been defunct for nearly a decade but I am unable to archive it.