Dry run option for Titlecase plugin

[KoreyF490]

I was looking through the plug-in docs for the newly released Titlecase plugin, and I haven't seen any options for when the plug-in is manually run to perform a dry run. I might be mistaken, but I think it would be nice to implement a dry run option to see the changes beforehand, and to see if there's something that's needs to be added to the preserve list before changing tags.