* Improve Route53 documentation
- Grammar fixes
- Formatting improvements
- Don't encourage using environment vars instead of the credentials file
* Add back sdk config link
- Fixed indentation
- Use same naming scheme for all examples
(i.e. all caps for provider, REG prefix for registrar)
- Use REG_NONE as registrar when provider does not provide it
- Use example.tld for example domain
- Use 1.2.3.1/24 IP range for examples
- A few spelling fixes
