make docbase.js config more friendly and generic
make docbase.js config more friendly and generic

Config changes:
* removes path option from tlf,
* now pick markdown files from github / file or a generic URL,
* remove conflicting options

Bug fixes:
* files were loaded from local paths even when user selects github, fixed that;
* allow files directly inside the version / root docs folder.

appbaseio/Docbase,appbaseio/Docbase