Clarifying interface for Lotus::Entity in README

Also synchronizing README and Lotus::Entity's inline comments.

Related to lotus/model#78

[skip ci]
Merge pull request #79 from jeremyf/updating-readme-regarding-lotus-model

Clarifying interface for Lotus::Entity in README
Addressing some of Inch CI's suggestion

Lotus::Model::Configuration

http://inch-ci.org/github/lotus/model
Expanding the AdapterRegistry documentation

This also involves tweaking the parameter names to reflect their
usage
Merge pull request #80 from jeremyf/wordsmithing

Addressing some of Inch CI's suggestion
[ci skip] Remove TODO, thanks to @jeremyf :+1: Ref lotus/model#81