Update docs, trim boilerplate
Add default values for config entries; and io.open

Add default values for missing config entries.
Also, use io.open/io.write instead of builtins so that .html files are
always read and written in windows format.  Jython requires io.open and
io.write to specify an encoding parameter (used 'ascii').
Start conversion of index.html to markdown
Can handle missing .json config file

Uses default config values if .json file is missing
Run pylint on convertmarkdown.py
Remove redundant 'title' entry in json config
WIP Convert index from html to markdown