Doc updates for customizing.txt, start of index generation customizing.txt: fix doc on schema.py. Documented obsolete db schema declaration/initial data method. doc on config.ini is incomplete. doc as such. Add doc for [rdbms]: backend, cache_size, sqlite_timeout document Interval schema type. Also change formatting for list of schema types to description list from regular list so types are more visible. add link to roundup wiki for schema chnge examples. fix formatting for postfix config. document Rest Access and Xmlrpc Access permissions; change classic schema.py example to include them. doc db/backend_name as obsolete, conf.py [rdbms] backend used instead. start adding index references conf.py: update copyright year index.txt: add link to genindex.html. _templates/layout.html: change code to make index output work. Not sure what the change does, just monkey pasting from sphinx basic/layout.html

--- a/doc/index.txt	Fri May 08 23:32:16 2020 -0400
+++ b/doc/index.txt	Mon May 11 00:02:31 2020 -0400
@@ -33,3 +33,8 @@
 
 See: https://wiki.roundup-tracker.org/ReleaseErrata for fixes to
 documentation.
+
+Indices
+=======
+ 
+* :ref:`genindex`