Add a README.md

[pbchase]

Add a README.md that reflects the repo description ("Fill a REDCap project with generated data based on the project design and a minimal set of inputs") and this text

Project goals and audience

This project aims to generate ample, rich test data for a new REDCap with little to no effort. This supports testing and development that requires data as input. It supports reporting writing when reports could need numerous records and rich input variation. It supports the creation of non-identifiable test data and the demonstration of REDCap functionality. It supports tests for missing data and bad data.
The audience for this package is R developers working in REDCap shops. They could use it to create data for their own development needs and the needs of their REDCap Admins and customers.

Limitations

This package is not a substitute for interactive testing of REDCap forms and surveys. For example, it cannot complete a survey through a survey engine.

This document will be the root page of the package documentation when we start writing vignettes. It should describe the feature set of the first release, but very little more.

Futures

We can have a "Futures" section, but it should be brief. The details of those futures should be described in Github issues and milestones. At the moment, the project plan is described at REDCapFilleR Design Notes

[pbchase]

https://ouhscbbmc.github.io/REDCapR/index.html has a good model for README content

[pbchase]

Addressed by PR #10