Improve README flow

[rossng]

Comments from Benjamin as part of #86

• Overall flow...
  • Separating Pre-Requisites from Setup as separate "phases" seems
    unnecessarily heavy.
  • Most of the README files begin with a sort of "Table of Contents" that
    makes subroutine calls to various sections of the rest of the document.
    This requires quite a bit of remembering state on the part of readers
    (especially since the whole README file is itself generally a subroutine
    call from the main README) and contributes to a feeling of overwhelm.
    Moreover, there is not very much material in any of the files besides
    the sections describing what to do.
  • So my suggestion for overall flow would be to
    1. Coalesce the pre-requisites and setup sections of every document
       into a single list
    2. Inline all the subroutine calls within individual README documents
       -- i.e., make the whole document be a list of ## sections each
       describing a major step of installation.
    3. For the few sections that contain miscellaneous notes and useful
       information, rather than setup instructions, just mark them clearly
       as "Notes" so the reader knows to skip over them on a first pass.
• Big tables at bottoms of files: Please let's just put the instructions
  for env variables directly in the .example files! There are many
  advantages to this:
  • documentation right next to where you need it
  • avoids a subroutine call to a different part of the README
  • no width restriction --> encouragement to document things more
    verbosely --> good

[rossng]

There's also a definite issue with the ordering of Auth0 relative to everything else. Need to figure out if there are circular deps between Auth0 setup and actions/frontend setup instructions.