Added more information about domains in packages

I was looking at the source and realized that someone could use a domain name that they don't use, such as .com, .net, etc. Although me.<YourNameHere>.PluginName would work iirc. 

So, I basically added so more detail on domains that I didn't notice, or that I simply missed.
Merge pull request #1 from AnUnknownMiner/master

Added more information about domains in packages