Introduce distinct doc/ and notes/ directories

doc/README.md

@@ -0,0 +1,11 @@
+## The doc/ directory
+   The `doc/` directory serves as home for documentation.  This is the place to
+   put refined documentation after it has gone through `notes/`.  The contents of
+   this directory should be accessible to a broad audience including prospective
+   users, active users, and developers.  Highly technical 
+
+   1.  The note authors and
+   2.  Developers of the project
+   
+   It need not be meaningful to casual users.
+