Update info for getting MaxMind GeoIP clientId and licenseKey

[UplandJacob]

What feature do you want to see added?

Update the comments in the config file with the new link to the EssentialsX page and explain what each option is named on the MaxMind website.

Are there any alternatives?

N/A

Anything else?

I was a little confused when I was setting it up myself because I didn't see a clientID on MaxMind. (I just tried the Account ID - it worked) So, this will clear things up.