Chores/move config

[rosalinekarr]

No task for this, just a refactor that would be nice to get in before 2.0, so I knocked it out in my spare time

Problem

Several methods on the config porcelain are only ever used within the SDK core and probably shouldn't be exposed to the user.

Solution

Move the "requireGet" methods into the core, added new porcelain config methods for the user and updated all imports accordingly.

Change summary:

• Moved the config module back into the core
• Added config porcelain to expose the config methods the user will need
• Updated config documentation