Related Issue(s): #

Proposed Changes:

1. Added a 'foundations' section to the overview, to talk about the various standards we rely on.
2. Clarified that 'null' is not the same as leaving a field out.

PR Checklist:

• This PR is made against the dev branch (all proposed changes except releases should be against dev, not master).
• This PR has no breaking changes.
• I have added my changes to the CHANGELOG or a CHANGELOG entry is not required.