Update glossary with field names used ubiquitously in extensions, to support clarity of in-line documentation in platform/core. WTD-573.
Add a Glossary section to the top-level README.md to aid in understanding terminology used throughout comments in platform/core. WTD-573.
Add top level README file describing, in broad terms, the structure of the project. In particular, this documents the naming conventions which support build and test, and provides a short summary of how these both run. WTD-519.