Add FAQs related to customer billing and invoicing

[benbridts]

There are several different ways that customers can pay their AWS / A-Cloud bills. They might have questions like:

• Will this have an effect on my billing preferences, consolidated billing, Enterprise Agreement or CloudFront Discounted Pricing?
• I'm currently getting invoices from "Amazon Web Services EMEA SARL" ("AWS Europe") or "[insert equivalent for other locations]". Will this change?

Edit, in more general terms the answer to "How do I switch from AWS to A-Cloud technology?" covers the technical concerns, not the administrative concerns.

[timbray]

Good point! Feel like suggesting some language?

[geoffarnold]

Great minds think alike. Let's use this issue to track customer identity and payments, and the other one I started for cybersecurity and privacy.