Don't titlecase HTML entity character references

[ChrisJohnNewton]

For example, I'm seeing & become &Amp;, which makes validation fail using my third-party HTML validator.

There is currently no workaround for this issue that I'm aware of because adding in & into the smallWords parameter doesn't work because line 85 in index.js expects an alphanumeric pattern. So you have to put amp instead of & into the smallWords set - which isn't ideal.

Great package by the way.

Thanks